Split migrations folder (#21549)

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

models/migrations/v1_12/v127.go

@@ -0,0 +1,45 @@
+// Copyright 2020 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_12 //nolint
+
+import (
+	"fmt"
+
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func AddLanguageStats(x *xorm.Engine) error {
+	// LanguageStat see models/repo_language_stats.go
+	type LanguageStat struct {
+		ID          int64 `xorm:"pk autoincr"`
+		RepoID      int64 `xorm:"UNIQUE(s) INDEX NOT NULL"`
+		CommitID    string
+		IsPrimary   bool
+		Language    string             `xorm:"VARCHAR(30) UNIQUE(s) INDEX NOT NULL"`
+		Percentage  float32            `xorm:"NUMERIC(5,2) NOT NULL DEFAULT 0"`
+		Color       string             `xorm:"-"`
+		CreatedUnix timeutil.TimeStamp `xorm:"INDEX CREATED"`
+	}
+
+	type RepoIndexerType int
+
+	// RepoIndexerStatus see models/repo_stats_indexer.go
+	type RepoIndexerStatus struct {
+		ID          int64           `xorm:"pk autoincr"`
+		RepoID      int64           `xorm:"INDEX(s)"`
+		CommitSha   string          `xorm:"VARCHAR(40)"`
+		IndexerType RepoIndexerType `xorm:"INDEX(s) NOT NULL DEFAULT 0"`
+	}
+
+	if err := x.Sync2(new(LanguageStat)); err != nil {
+		return fmt.Errorf("Sync2: %w", err)
+	}
+	if err := x.Sync2(new(RepoIndexerStatus)); err != nil {
+		return fmt.Errorf("Sync2: %w", err)
+	}
+	return nil
+}