Changes the text in the Revert merge request modal: `Start a new merge request with these changes` => `Start a new merge request with the revert changes`.

Html code now works in commits atom feed `title` and `summary`.

Put back non triggered information

Signed-off-by: Rémy Coutable <remy@rymai.me>

When a new user confirm his email the signin tab is correctly shown.

Adds `#build_notification_recipients` to `NotificationRecipientService`
that returns the `NotificationRecipient` objects in order to be able to
access the new attribute `reason`.

This new attribute is used in the different notifier methods in order to
add the reason as a header: `X-GitLab-NotificationReason`.

Only the reason with the most priority gets sent.

[10.3] Migrate `can_push` column from `keys` to `deploy_keys_project`

See merge request gitlab/gitlabhq!2276

(cherry picked from commit f6ca52d31bac350a23938e0aebf717c767b4710c)

1f2bd3c0 Backport to 10.3

target branch select dropdown doesnt care about tags so we dont need to waste time searching them

Remove block + interpolation to simplify the calls to link helpers

Closes #42059

Removes explanation text for non triggered job
Adds tests

Remove duplicate ee code

This was generalized for usage in the new variable table design, see
https://gitlab.com/gitlab-org/gitlab-ce/issues/39118#note_53615249

Conflicts:
	app/assets/stylesheets/pages/projects.scss
	ee/app/assets/javascripts/protected_branches/protected_branch_create.js
	ee/app/assets/javascripts/protected_tags/protected_tag_create.js
	ee/app/views/projects/protected_branches/ee/_dropdown.html.haml