Bulk upload suppress emails

[matthewhilton]

Changes

• Adds a checkbox to suppress emails when bulk uploading, to bring it in alignment with the manual assignment page.
• A few fixups to the code that were causing debugging messages:
  • Output before redirect
  • Context being set when it didn't need to be (and was trying to set a different context)
  • Undefined var $courseid
  • Undefined var $session
  • Removed unused import

Testing

• Manual testing - works as expected.
• Also covered by unit tests

[keevan]

Overall the changes here looks good. Thanks for adding in the tests.

Are you able to consider the feedback comments and once ready, add a commit to also bump the version.

Also noting that ideally this would land in 403 stable before it is backported to 400. Perhaps we should merge it in that order, if you could prepare a PR for that.

Thanks @matthewhilton.

[matthewhilton]

Confirming I have rebased and changed the target to MOODLE_403_STABLE

Note - After locally testing this, I found a new error: Exception - Undefined constant "mod_facetoface\form\FILE_INTERNAL" when loading the form to upload the csv.
This seems to be caused by the reordering of the $OUTPUT->header (i.e. it was being implicitly included before). I have added another commit to explicitly include these files as well.

[keevan]

Looks good. Thanks for making the changes Matt.