Ensure deleted parent directory tombstones are overwritten when implicitly recreated

As discussed on HADOOP-13998, there may be a test missing (and possibly broken metadata store implementations) for the case where a directory is deleted but is later implicitly recreated by creating a file inside it, where the tombstone is not overwritten. In such a case, listing the parent directory would result in an error.

This may also be happening because of HADOOP-14457, but we should add a test for this other possibility anyway and fix it if it fails with any implementations.