Monitor all git commands; move blame to git package and replace git as a variable (#6864)

* monitor all git commands; move blame to git package and replace git as a variable

* use git command but not other commands

* fix build

* move exec.Command to git.NewCommand

* fix fmt

* remove unrelated changes

* remove unrelated changes

* refactor IsEmpty and add tests

* fix tests

* fix tests

* fix tests

* fix tests

* remove gitLogger

* fix fmt

* fix isEmpty

* fix lint

* fix tests

models/release.go

@@ -434,7 +434,7 @@ func DeleteReleaseByID(id int64, u *User, delTag bool) error {
 	if delTag {
 		_, stderr, err := process.GetManager().ExecDir(-1, repo.RepoPath(),
 			fmt.Sprintf("DeleteReleaseByID (git tag -d): %d", rel.ID),
-			"git", "tag", "-d", rel.TagName)
+			git.GitExecutable, "tag", "-d", rel.TagName)
 		if err != nil && !strings.Contains(stderr, "not found") {
 			return fmt.Errorf("git tag -d: %v - %s", err, stderr)
 		}