Add an abstract json layout to make it's easier to change json library (#16528)

* Add an abstract json layout to make it's easier to change json library

* Fix import

* Fix import sequence

* Fix blank lines

* Fix blank lines

models/migrations/v130.go

@@ -5,8 +5,8 @@
 package migrations
 
 import (
+	"code.gitea.io/gitea/modules/json"
 	"code.gitea.io/gitea/modules/setting"
-	jsoniter "github.com/json-iterator/go"
 
 	"xorm.io/xorm"
 )
@@ -70,7 +70,6 @@ func expandWebhooks(x *xorm.Engine) error {
 
 		for _, res := range results {
 			var events HookEvent
-			json := jsoniter.ConfigCompatibleWithStandardLibrary
 			if err = json.Unmarshal([]byte(res.Events), &events); err != nil {
 				return err
 			}