Fix #5997.

If a push causes the patch/diff of a PR towards target branch to change, all existing reviews for the PR will be set and shown as stale.
New branch protection option to dismiss stale approvals are added.
To show that a review is not based on the latest PR changes, an hourglass is shown

* Add branch protection option to block merge on requested changes.

* Add migration step

* Fix check to correct negation

* Apply suggestions from code review

Language improvement.

Co-Authored-By: John Olheiser <42128690+jolheiser@users.noreply.github.com>

* Copyright year.

Co-authored-by: John Olheiser <42128690+jolheiser@users.noreply.github.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

* Possibility to not use whitelist but allow anyone with write access

* fix existing test

* rename migration function

* Try to give a better name for migration step

* Clear settings if higher level setting is not set

* Move official reviews to db instead of counting approvals each time

* migration

* fix

* fix migration

* fix migration

* Remove NOT NULL from EnableWhitelist as migration isn't possible

* Fix migration, reviews are connected to issues.

* Fix SQL query issues in GetReviewersByPullID.

* Simplify function GetReviewersByIssueID

* Handle reviewers that has been deleted

* Ensure reviews for test is in a well defined order

* Only clear and set official reviews when it is an approve or reject.

* add missing "d"

* CI.redo()

Add an option to protected branches to add writing deploy keys to the whitelist for pushing.

Please note this is technically a breaking change: previously if the owner of a repository was on the whitelist then any writing deploy key was effectively on the whitelist. This option will now need to be set if that is desired.

Closes #8472 

Details:
* Allow Protected Branches to Whitelist Deploy Keys
* Add migration
* Ensure that IsDeployKey is set to false on the http pushes
* add not null default false

* refuse merge until ci successfully

* deny merge request when required status checkes not succeed on merge Post and API

* add database migration for added columns on protected_branch

* fix migration

* fix protected branch check bug

* fix protected branch settings

* remove duplicated code on check pull request's required commit statuses pass

* remove unused codes

* fix migration

* add newline for template file

* fix go mod

* rename function name and some other fixes

* fix template

* fix bug pull view

* remove go1.12 wrong dependencies

* add administrator bypass when protected branch status check enabled

* fix bug

* improve the codes

* Add branch protection for approvals

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add required approvals

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add missing comments and fmt

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add type = approval and group by reviewer_id to review

* Prevent users from adding negative review limits

* Add migration for approval whitelists

Signed-off-by: Jonas Franz <info@jonasfranz.software>

* Add database migrations for merge whitelist

* Add merge whitelist settings for protected branches

* Add checks for merge whitelists

* improve protected branch to add whitelist support

* fix lint

* fix style check

* fix tests

* fix description on UI and import

* fix test

* bug fixed

* fix tests and languages

* move isSliceInt64Eq to util pkg; improve function names & typo