Fix handling for empty checkboxes fieldtype on front-end

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).

[jasonvarga]

Continuation of #7178

Previously, if you uncheck all the boxes in a checkboxes field on the frontend, it would act like the field wasn't submitted at all, so the previous value would be used.

This PR adds a hidden field with an empty value. So if you uncheck all the options, an empty value still gets submitted, so the value will be updated to nothing, as expected.

Added a test to ensure that the hidden field is in the html.
Add equivalent test for toggle field while we're at it, which relies on the same behavior.

Again, this only matters for #6400 since at the moment front-end fields are only used for forms, which are create-only at the moment.

[what-the-diff]

• Added a hidden input to the checkboxes field.
• Changed how multiple select fields are rendered when no value is selected, so that an empty array is returned instead of null (which was causing issues with validation).