[TASK] DB-Browser: Pagetree shown even though tables only allow rootLevel

If only tables with rootLevel=1 in TCA are allowed
to select records from, the pagetree is irritating.

Resolves: #47436
Releases: 6.2
Change-Id: I10e3d8e50e94243407f859a8c83feae82891a572
Reviewed-on: https://review.typo3.org/20073
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters