refactor: make git package handle all git operations (#38543)

before: gitrepo vs git packages
after: git package fully handle all git operations

by the way, use `WithRepo(repo)` instead of `WithDir(repo.Path)` to hide
path details.

benefits:

1. remove all unnecessary wrappers, developers no need to struggle with
"which package should be used"
2. simplify code, RepositoryFacade can (will) be used everywhere, all
"path" details are (will be) hidden

modules/lfs/pointer_scanner_nogogit.go

@@ -41,7 +41,7 @@ func SearchPointerBlobs(ctx context.Context, repo *git.Repository, pointerChan c
 
 	// 3. Take the shas of the blobs and batch read them
 	wg.Go(func() error {
-		return pipeline.CatFileBatch(ctx, cmd3BatchContent, repo.Path)
+		return pipeline.CatFileBatch(ctx, cmd3BatchContent, repo)
 	})
 
 	// 2. From the provided objects restrict to blobs <=1k
@@ -51,7 +51,7 @@ func SearchPointerBlobs(ctx context.Context, repo *git.Repository, pointerChan c
 
 	// 1. Run batch-check on all objects in the repository
 	wg.Go(func() error {
-		return pipeline.CatFileBatchCheckAllObjects(ctx, cmd1AllObjs, repo.Path)
+		return pipeline.CatFileBatchCheckAllObjects(ctx, cmd1AllObjs, repo)
 	})
 	err := wg.Wait()
 	close(pointerChan)