Fix schedule tasks bugs (#28691)

Fix #28157 

This PR fix the possible bugs about actions schedule.

## The Changes

- Move `UpdateRepositoryUnit` and `SetRepoDefaultBranch` from models to
service layer
- Remove schedules plan from database and cancel waiting & running
schedules tasks in this repository when actions unit has been disabled
or global disabled.
- Remove schedules plan from database and cancel waiting & running
schedules tasks in this repository when default branch changed.

modules/webhook/type.go

@@ -31,6 +31,7 @@ const (
 	HookEventRepository                HookEventType = "repository"
 	HookEventRelease                   HookEventType = "release"
 	HookEventPackage                   HookEventType = "package"
+	HookEventSchedule                  HookEventType = "schedule"
 )
 
 // Event returns the HookEventType as an event string