Add "Update Branch" button to Pull Requests (#9784)

* add Divergence

* add Update Button

* first working version

* re-use code

* split raw merge commands and db-change functions (notify, cache, ...)

* use rawMerge (remove redundant code)

* own function to get Diverging of PRs

* use FlashError

* correct Error Msg

* hook is triggerd ... so remove comment

* add "branch2" to "user2/repo1" because it unit-test "TestPullView_ReviewerMissed" use it but dont exist jet :/

* move GetPerm to IsUserAllowedToUpdate

* add Flash Success MSG

* imprufe code
- remove useless js chage

* fix-lint

* TEST: add PullRequest ID:5
Repo: user2/repo1
Base: branch1
Head: pr-to-update

* correct comments

* make PR5 outdated

* fix Tests

* WIP: add pull update test

* update revs

* update locales

* working TEST

* update UI

* misspell

* change style

* add 1s delay so rev exist

* move row up (before merge row)

* fix lint nit

* UI remove divider

* Update style

* nits

* do it right

* introduce IsSameRepo

* remove useless check

Co-authored-by: Lauris BH <lauris@nix.lv>

options/locale/locale_en-US.ini

@@ -1082,6 +1082,10 @@ pulls.open_unmerged_pull_exists = `You cannot perform a reopen operation because
 pulls.status_checking = Some checks are pending
 pulls.status_checks_success = All checks were successful
 pulls.status_checks_error = Some checks failed
+pulls.update_branch = Update branch
+pulls.update_branch_success = Branch update was successful
+pulls.update_not_allowed = You are not allowed to update branch
+pulls.outdated_with_base_branch = This branch is out-of-date with the base branch
 
 milestones.new = New Milestone
 milestones.open_tab = %d Open