Sync branches into databases (#22743)

Related #14180
Related #25233 
Related #22639
Close #19786
Related #12763 

This PR will change all the branches retrieve method from reading git
data to read database to reduce git read operations.

- [x] Sync git branches information into database when push git data
- [x] Create a new table `Branch`, merge some columns of `DeletedBranch`
into `Branch` table and drop the table `DeletedBranch`.
- [x] Read `Branch` table when visit `code` -> `branch` page
- [x] Read `Branch` table when list branch names in `code` page dropdown
- [x] Read `Branch` table when list git ref compare page
- [x] Provide a button in admin page to manually sync all branches.
- [x] Sync branches if repository is not empty but database branches are
empty when visiting pages with branches list
- [x] Use `commit_time desc` as the default FindBranch order by to keep
consistent as before and deleted branches will be always at the end.

---------

Co-authored-by: Jason Song <i@wolfogre.com>

services/pull/update.go

@@ -7,7 +7,6 @@ import (
 	"context"
 	"fmt"
 
-	"code.gitea.io/gitea/models"
 	git_model "code.gitea.io/gitea/models/git"
 	issues_model "code.gitea.io/gitea/models/issues"
 	access_model "code.gitea.io/gitea/models/perm/access"
@@ -168,7 +167,7 @@ func GetDiverging(ctx context.Context, pr *issues_model.PullRequest) (*git.Diver
 	log.Trace("GetDiverging[%-v]: compare commits", pr)
 	prCtx, cancel, err := createTemporaryRepoForPR(ctx, pr)
 	if err != nil {
-		if !models.IsErrBranchDoesNotExist(err) {
+		if !git_model.IsErrBranchNotExist(err) {
 			log.Error("CreateTemporaryRepoForPR %-v: %v", pr, err)
 		}
 		return nil, err