[MM-23019] Create use_group_mentions permission and migrate existing roles (#13987)

* MM-22962 Create use_group_mentions permission and give to all non guest roles that can create post

* Add use_group_mentions to team admin role for test

* Trigger CI

* MM-22962 Remove old migration keys

model/migration.go

@@ -16,4 +16,5 @@ const (
 	MIGRATION_KEY_VIEW_MEMBERS_NEW_PERMISSION                 = "view_members_new_permission"
 	MIGRATION_KEY_ADD_MANAGE_GUESTS_PERMISSIONS               = "add_manage_guests_permissions"
 	MIGRATION_KEY_CHANNEL_MODERATIONS_PERMISSIONS             = "channel_moderations_permissions"
+	MIGRATION_KEY_ADD_USE_GROUP_MENTIONS_PERMISSION           = "add_use_group_mentions_permission"
 )