Add CC/BCC fields for Sensei emails

[merkushin]

Resolves #7001

In this PR:

• I moved adding our fields to Sensei_Settings class, to have only one place for all fields.
• I used a custom type for the field ("email_list") and a corresponding validation methods.
• These methods don't remove duplicated emails. Wasn't sure if we need it. Also it will affect validation in its current state.

Proposed Changes

• Add CC/BCC fields for Sensei emails.

Testing Instructions

1. Go to Sensei LMS -> Settings -> Email -> Settings.
2. Try to set invalid emails for CC & BCC.
3. It is expected to see an error message for each field.
4. Set different emails for CC and BCC.
5. Create a course with lessons.
6. Take the course as a student and complete it.
7. Check your emails. It is expected to get an email in accounts you set for CC & BCC. The email that was sent to BCC shouldn't have that address in recipients.

Deprecated Code

• Sensei\Internal\Emails\Email_Settings_Tab::add_reply_to_setting – adding of these settings moved to \Sensei_Settings.

Pre-Merge Checklist

• PR title and description contain sufficient detail and accurately describe the changes
• Acceptance criteria is met
• Decisions are publicly documented
• Adheres to coding standards (PHP, JavaScript, CSS, HTML)
• All strings are translatable (without concatenation, handles plurals)
• Follows our naming conventions (P6rkRX-4oA-p2)
• Hooks (p6rkRX-1uS-p2) and functions are documented
• New UIs are responsive and use a mobile-first approach
• New UIs match the designs
• Different user privileges (admin, teacher, subscriber) are tested as appropriate
• Code is tested on the minimum supported PHP and WordPress versions
• User interface changes have been tested on the latest versions of Chrome, Firefox and Safari
• "Needs Documentation" label is added if this change requires updates to documentation
• Known issues are created as new GitHub issues

[donnapep]

@merkushin Did you mean to add a reviewer to this or does it still need some work?

[merkushin]

@donnapep oops, looks like I forgot to add reviewers🤦🏻‍♂️

[donnapep]

For validation, could we reuse the same validation strategy that is currently being used for the other email addresses for consistency's sake?

[donnapep]

If we make the type email and add the multiple attribute, it should work with multiple email addresses.

[merkushin]

Hum, I'll try it. But I think that produces multiple fields, doesn't it?

[merkushin]

I found what you meant. Trying to use it.

[merkushin]

@donnapep

For validation, could we reuse the same validation strategy that is currently being used for the other email addresses for consistency's sake?

I think it works only for a single email in the field. That's the browser validation that comes with the email input type. It is good to have it, but we should have a counterpart on the backend. Anyway, I'll try it with #7014 (comment)

[codecov]

Codecov Report

Merging #7014 (49d83b6) into trunk (7dbccb4) will increase coverage by 1.07%.
Report is 1 commits behind head on trunk.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##              trunk    #7014      +/-   ##
============================================
+ Coverage     48.07%   49.15%   +1.07%     
- Complexity    10467    10470       +3     
============================================
  Files           573      573              
  Lines         44164    44218      +54     
  Branches        402      402              
============================================
+ Hits          21234    21736     +502     
+ Misses        22603    22155     -448     
  Partials        327      327              

Files Changed	Coverage Δ
includes/class-sensei.php	23.52% <ø> (ø)
includes/class-sensei-settings-api.php	15.47% <100.00%> (+3.84%)	⬆️
includes/class-sensei-settings.php	70.70% <100.00%> (+65.78%)	⬆️
includes/internal/emails/class-email-sender.php	99.02% <100.00%> (+0.03%)	⬆️
...ludes/internal/emails/class-email-settings-tab.php	85.82% <100.00%> (-12.41%)	⬇️

... and 1 file with indirect coverage changes

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[merkushin]

@donnapep I updated the PR.

[m1r0]

Looks good and tests well. 👍

[m1r0]

Just curious, does it make sense to have tests for these fields?

[merkushin]

Thanks @m1r0. Added tests.

[m1r0]

Thank you! 🙇