Allow Protected Branches to Whitelist Deploy Keys (#8483)

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

cmd/serv.go

@@ -191,6 +191,8 @@ func runServ(c *cli.Context) error {
 	os.Setenv(models.EnvPusherID, strconv.FormatInt(results.UserID, 10))
 	os.Setenv(models.ProtectedBranchRepoID, strconv.FormatInt(results.RepoID, 10))
 	os.Setenv(models.ProtectedBranchPRID, fmt.Sprintf("%d", 0))
+	os.Setenv(models.EnvIsDeployKey, fmt.Sprintf("%t", results.IsDeployKey))
+	os.Setenv(models.EnvKeyID, fmt.Sprintf("%d", results.KeyID))
 
 	//LFS token authentication
 	if verb == lfsAuthenticateVerb {