Sync branches into databases (go-gitea#22743)

Related go-gitea#14180
Related go-gitea#25233 
Related go-gitea#22639
Close go-gitea#19786
Related go-gitea#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/error.go

@@ -318,90 +318,6 @@ func (err ErrFilePathProtected) Unwrap() error {
 	return util.ErrPermissionDenied
 }
 
-// __________                             .__
-// \______   \____________    ____   ____ |  |__
-//  |    |  _/\_  __ \__  \  /    \_/ ___\|  |  \
-//  |    |   \ |  | \// __ \|   |  \  \___|   Y  \
-//  |______  / |__|  (____  /___|  /\___  >___|  /
-//         \/             \/     \/     \/     \/
-
-// ErrBranchDoesNotExist represents an error that branch with such name does not exist.
-type ErrBranchDoesNotExist struct {
-	BranchName string
-}
-
-// IsErrBranchDoesNotExist checks if an error is an ErrBranchDoesNotExist.
-func IsErrBranchDoesNotExist(err error) bool {
-	_, ok := err.(ErrBranchDoesNotExist)
-	return ok
-}
-
-func (err ErrBranchDoesNotExist) Error() string {
-	return fmt.Sprintf("branch does not exist [name: %s]", err.BranchName)
-}
-
-func (err ErrBranchDoesNotExist) Unwrap() error {
-	return util.ErrNotExist
-}
-
-// ErrBranchAlreadyExists represents an error that branch with such name already exists.
-type ErrBranchAlreadyExists struct {
-	BranchName string
-}
-
-// IsErrBranchAlreadyExists checks if an error is an ErrBranchAlreadyExists.
-func IsErrBranchAlreadyExists(err error) bool {
-	_, ok := err.(ErrBranchAlreadyExists)
-	return ok
-}
-
-func (err ErrBranchAlreadyExists) Error() string {
-	return fmt.Sprintf("branch already exists [name: %s]", err.BranchName)
-}
-
-func (err ErrBranchAlreadyExists) Unwrap() error {
-	return util.ErrAlreadyExist
-}
-
-// ErrBranchNameConflict represents an error that branch name conflicts with other branch.
-type ErrBranchNameConflict struct {
-	BranchName string
-}
-
-// IsErrBranchNameConflict checks if an error is an ErrBranchNameConflict.
-func IsErrBranchNameConflict(err error) bool {
-	_, ok := err.(ErrBranchNameConflict)
-	return ok
-}
-
-func (err ErrBranchNameConflict) Error() string {
-	return fmt.Sprintf("branch conflicts with existing branch [name: %s]", err.BranchName)
-}
-
-func (err ErrBranchNameConflict) Unwrap() error {
-	return util.ErrAlreadyExist
-}
-
-// ErrBranchesEqual represents an error that branch name conflicts with other branch.
-type ErrBranchesEqual struct {
-	BaseBranchName string
-	HeadBranchName string
-}
-
-// IsErrBranchesEqual checks if an error is an ErrBranchesEqual.
-func IsErrBranchesEqual(err error) bool {
-	_, ok := err.(ErrBranchesEqual)
-	return ok
-}
-
-func (err ErrBranchesEqual) Error() string {
-	return fmt.Sprintf("branches are equal [head: %sm base: %s]", err.HeadBranchName, err.BaseBranchName)
-}
-
-func (err ErrBranchesEqual) Unwrap() error {
-	return util.ErrInvalidArgument
-}
-
 // ErrDisallowedToMerge represents an error that a branch is protected and the current user is not allowed to modify it.
 type ErrDisallowedToMerge struct {
 	Reason string

models/fixtures/branch.yml

@@ -0,0 +1,47 @@
+-
+  id: 1
+  repo_id: 1
+  name: 'foo'
+  commit_id: '65f1bf27bc3bf70f64657658635e66094edbcb4d'
+  commit_message: 'first commit'
+  commit_time: 978307100
+  pusher_id: 1
+  is_deleted: true
+  deleted_by_id: 1
+  deleted_unix: 978307200
+
+-
+  id: 2
+  repo_id: 1
+  name: 'bar'
+  commit_id: '62fb502a7172d4453f0322a2cc85bddffa57f07a'
+  commit_message: 'second commit'
+  commit_time: 978307100
+  pusher_id: 1
+  is_deleted: true
+  deleted_by_id: 99
+  deleted_unix: 978307200
+
+-
+  id: 3
+  repo_id: 1
+  name: 'branch2'
+  commit_id: '985f0301dba5e7b34be866819cd15ad3d8f508ee'
+  commit_message: 'make pull5 outdated'
+  commit_time: 1579166279
+  pusher_id: 1
+  is_deleted: false
+  deleted_by_id: 0
+  deleted_unix: 0
+
+-
+  id: 4
+  repo_id: 1
+  name: 'master'
+  commit_id: '65f1bf27bc3bf70f64657658635e66094edbcb4d'
+  commit_message: 'Initial commit'
+  commit_time: 1489927679
+  pusher_id: 1
+  is_deleted: false
+  deleted_by_id: 0
+  deleted_unix: 0