BREAKING CHANGE: replace Airflow config by conx extras in SMTP provider

[hussein-awala]

This PR introduces some breaking changes to SMTP provider:

The argument from_email is now an optional kwarg in SmtpNotifier, and the argument to became the first positional argument.

Configuring the SmtpNotifier and SmtpHook default values via Airflow SMTP configurations is not supported anymore. You can instead use the SMTP connection configuration to set the default values, where you can use:

• the connection extra field ssl_context instead of the configuration smtp_provider.ssl_context or email.ssl_context in the SMTP hook.
• the connection extra field from_email instead of the configuration smtp.smtp_mail_from in SmtpNotifier.
• the connection extra field subject_template instead of the configuration smtp.templated_email_subject_path in SmtpNotifier.
• the connection extra field html_content_template instead of the configuration smtp.templated_html_content_path in SmtpNotifier.

[eladkal]

Just needs to remove unrelated changes for mongo (as were already fixed in main)

[eladkal]

@hussein-awala can you rebase and resolve conflicts?
I'd like to include this in the next provider wave

[hussein-awala]

@hussein-awala can you rebase and resolve conflicts? I'd like to include this in the next provider wave

it's ready, I'll merge once the tests are green

[eladkal]

Merging. Failures ade about Amazon DMS not related to this PR