Add tag protection (#15629)

* Added tag protection in hook.

* Prevent UI tag creation if protected.

* Added settings page.

* Added tests.

* Added suggestions.

* Moved tests.

* Use individual errors.

* Removed unneeded methods.

* Switched delete selector.

* Changed method names.

* No reason to be unique.

* Allow editing of protected tags.

* Removed unique key from migration.

* Added docs page.

* Changed date.

* Respond with 404 to not found tags.

* Replaced glob with regex pattern.

* Added support for glob and regex pattern.

* Updated documentation.

* Changed white* to allow*.

* Fixed edit button link.

* Added cancel button.

Co-authored-by: zeripath <art27@cantab.net>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/models.go

@@ -137,6 +137,7 @@ func init() {
 		new(IssueIndex),
 		new(PushMirror),
 		new(RepoArchiver),
+		new(ProtectedTag),
 	)
 
 	gonicNames := []string{"SSL", "UID"}