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

Signed-off-by: Tamal Saha <tamal@appscode.com>

* Fix #6946 by checking PullRequest ID on pushing

* Ensure we have the owner name, the pr attributes and the the issue

* Fix TestSearchRepo by waiting till indexing is done

* Update integrations/repo_search_test.go

* changes as per @mrsdizzie

* missing comma

* Spelling mistake

* Fix full pushing environment

* remove push_update

* move models.PushUpdate to repofiles.PushUpdate

* Move hook functionality internally

* Internalise serv logic

* Remove old internal paths

* finally remove the gitlogger

* Disallow push on archived repositories

* fix lint error

* Update modules/private/key.go

* Update routers/private/hook.go

* Update routers/private/hook.go

* Update routers/private/hook.go

* Updated routers/private/serv.go

* Fix LFS Locks over SSH

* rev-list needs to be run by the hook process

* fixup

* Improve git test

* Ensure that the lfs files are created with a different prefix

* Reduce the replication in git_test.go

* slight refactor

* Remove unnecessary "/"

* Restore ensureAnonymousClone

* Restore ensureAnonymousClone

* Run rev-list on server side

* Try passing in the alternative directories instead

* Mark test as skipped

* Improve git test

* Ensure that the lfs files are created with a different prefix
* Reduce the replication in git_test.go
* Remove unnecessary "/"