Move issues related files into models/issues (#19931)

* Move access and repo permission to models/perm/access

* fix test

* fix git test

* Move functions sequence

* Some improvements per @KN4CK3R and @delvh

* Move issues related code to models/issues

* Move some issues related sub package

* Merge

* Fix test

* Fix test

* Fix test

* Fix test

* Rename some files

modules/eventsource/manager_run.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/models"
+	issues_model "code.gitea.io/gitea/models/issues"
 	"code.gitea.io/gitea/modules/convert"
 	"code.gitea.io/gitea/modules/graceful"
 	"code.gitea.io/gitea/modules/json"
@@ -84,7 +85,7 @@ loop:
 			then = now
 
 			if setting.Service.EnableTimetracking {
-				usersStopwatches, err := models.GetUIDsAndStopwatch()
+				usersStopwatches, err := issues_model.GetUIDsAndStopwatch()
 				if err != nil {
 					log.Error("Unable to get GetUIDsAndStopwatch: %v", err)
 					return