Use the EnforcedStyleForMultiline: no_comma option.

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

merge_request_for_resolving_discussions ->
merge_request_to_resolve_discussions_of

By using `>`-quote style instead of `>>>`.

Also: Update documentation images.

And deduplicate the finding of MR's & discussions. Now the searching
is done in the service, istead of the controller & the API.

Delegate a discussion in a merge request into a new issue.
The discussion wil be marked as resolved and a system note will be
added linking to the newly created issue.

When a merge request can only be merged when all discussions are
resolved. This feature allows to easily delegate those discussions to a
new issue, while marking them as resolved in the merge request.

The user is presented with a new issue, prepared with mentions of all
unresolved discussions, including the first unresolved note of the
discussion, time and link to the note.

When the issue is created, the discussions in the merge request will get
a system note directing the user to the newly created issue.