Split migrations folder (#21549)

There are too many files in `models/migrations` folder so that I split
them into sub folders.

models/migrations/v1_10/v88.go

@@ -0,0 +1,66 @@
+// Copyright 2019 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package v1_10 //nolint
+
+import (
+	"crypto/sha1"
+	"fmt"
+
+	"xorm.io/xorm"
+)
+
+func hashContext(context string) string {
+	return fmt.Sprintf("%x", sha1.Sum([]byte(context)))
+}
+
+func AddCommitStatusContext(x *xorm.Engine) error {
+	type CommitStatus struct {
+		ID          int64  `xorm:"pk autoincr"`
+		ContextHash string `xorm:"char(40) index"`
+		Context     string `xorm:"TEXT"`
+	}
+
+	if err := x.Sync2(new(CommitStatus)); err != nil {
+		return err
+	}
+
+	sess := x.NewSession()
+	defer sess.Close()
+
+	start := 0
+	for {
+		statuses := make([]*CommitStatus, 0, 100)
+		err := sess.OrderBy("id").Limit(100, start).Find(&statuses)
+		if err != nil {
+			return err
+		}
+		if len(statuses) == 0 {
+			break
+		}
+
+		if err = sess.Begin(); err != nil {
+			return err
+		}
+
+		for _, status := range statuses {
+			status.ContextHash = hashContext(status.Context)
+			if _, err := sess.ID(status.ID).Cols("context_hash").Update(status); err != nil {
+				return err
+			}
+		}
+
+		if err := sess.Commit(); err != nil {
+			return err
+		}
+
+		if len(statuses) < 100 {
+			break
+		}
+
+		start += len(statuses)
+	}
+
+	return nil
+}