[4.x] Blueprint UI

[jasonvarga]

This improves the UI of the new blueprint tabs, and other related things.

• Makes the rough stuff I just dropped into [4.x] Blueprints sections and tabs #7669 look pretty (and adjusts logic to allow for said prettiness - e.g moving the tab fields into a modal)
• Organizes fieldtype settings into sections.
• Fieldtypes can define sections in their $configFields property.
• Fieldtype settings has a more scannable side by side field layout.
• Improves the look of other blueprint related stuff.
• Improves the look of modals.
• Asset blueprint/edit can have sections.
• Fixes a couple of issues that were leftover from [4.x] Blueprints sections and tabs #7669 like the Asset editor and Nav page editor not loading fields.
• Fixes list fieldtype empty state. (Potential conflict with [4.x] Fix list fieldtype #7736 but we'll consolidate over there.)
• Ability to hide the entire display label section by adding hide_meta: true to a field config. (Potential conflict with Ability to hide display field #6301)

Todo:

• Empty "sets" state when editing a bard/replicator field's settings.
• Add tests for the Fieldtype config blueprint changes, and cleanup because its a bit messy.