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>

models/repo.go

@@ -147,7 +147,7 @@ func DeleteRepository(doer *user_model.User, uid, repoID int64) error {
 		&repo_model.Collaboration{RepoID: repoID},
 		&issues_model.Comment{RefRepoID: repoID},
 		&git_model.CommitStatus{RepoID: repoID},
-		&git_model.DeletedBranch{RepoID: repoID},
+		&git_model.Branch{RepoID: repoID},
 		&git_model.LFSLock{RepoID: repoID},
 		&repo_model.LanguageStat{RepoID: repoID},
 		&issues_model.Milestone{RepoID: repoID},