Adjust object format interface (#28469)

- Remove `ObjectFormatID`
- Remove function `ObjectFormatFromID`.
- Use `Sha1ObjectFormat` directly but not a pointer because it's an
empty struct.
- Store `ObjectFormatName` in `repository` struct

modules/git/object_id_gogit.go

@@ -12,7 +12,7 @@ import (
 func ParseGogitHash(h plumbing.Hash) ObjectID {
 	switch hash.Size {
 	case 20:
-		return ObjectFormatFromID(Sha1).MustID(h[:])
+		return Sha1ObjectFormat.MustID(h[:])
 	}
 
 	return nil