API: Use find_branch! in all places
What does this MR do?
Use find_branch!
helper whenever possible in the API.
What are the relevant issue numbers?
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/51250
Does this MR meet the acceptance criteria?
-
Changelog entry added, if necessary - [-] Documentation created/updated
- [-] Tests added for this feature/bug
-
Conforms to the code review guidelines -
Conforms to the merge request performance guidelines -
Conforms to the style guides - [-] Conforms to the database guides
@rymai Can you take a look on that one?