- Create ci/lints controller inside project/
- Move js pages to be inside projects/
- Copy view ci/lint view to be inside project folder
- Remove ci/lint view and js files

Closes #43603

Closes #28857

Fixes attempts to update a service integration which had `can_test?`
set to true but validations were causing the "Test and save changes"
button to return "Something went wrong on our end."

Removes references to index action left from 0af99433

When a project uses fast-forward merging strategy user has
to rebase MRs to target branch before it can be merged.
Now user can do rebase in UI by clicking 'Rebase' button
instead of doing rebase locally.

This feature was already present in EE, this is only backport
of the feature to CE. Couple of changes:
* removed rebase license check
* renamed migration (changed timestamp)

Closes #40301

Closes #38741

* new merge request can be created by sending an email to the specific
email address (similar to creating issues by email)
* for the first iteration, source branch must be specified in the mail
subject, other merge request parameters can not be set yet
* user should enable "Receive notifications about your own activity" in
user settings to receive a notification about created merge request

Part of #32878