[BUGFIX] orphan_records show extension manager tables

Configure the extension manager tables for a valid
orphan_records check in the lowlevel cleaner. Allow
the records on the root level.

Resolves: #55893
Releases: 6.2, 6.1
Change-Id: I0a00e329fbc56e80b07b452b533c6cf2b877019c
Reviewed-on: http://review.typo3.org/35138
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>