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

modules/setting/setting_test.go

@@ -7,7 +7,8 @@ package setting
 import (
 	"testing"
 
-	jsoniter "github.com/json-iterator/go"
+	"code.gitea.io/gitea/modules/json"
+
 	"github.com/stretchr/testify/assert"
 )
 
@@ -28,6 +29,5 @@ func TestMakeAbsoluteAssetURL(t *testing.T) {
 
 func TestMakeManifestData(t *testing.T) {
 	jsonBytes := MakeManifestData(`Example App '\"`, "https://example.com", "https://example.com/foo/bar")
-	json := jsoniter.ConfigCompatibleWithStandardLibrary
 	assert.True(t, json.Valid(jsonBytes))
 }