[BUGFIX] Load adminPanel styles for FE editing

This patch enables frontend editing even if the adminPanel is closed
(minimized). Before adminPanel AND editing tab have to be opened which
isn't really user-friendly.

Resolves: #55896
Releases: 6.2
Change-Id: I892fe72380c3ede326f3da708dd5d495667eb09e
Reviewed-on: https://review.typo3.org/27557
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Pascal Dürsteler
Tested-by: Pascal Dürsteler
Reviewed-by: Xavier Perseguers
Reviewed-by: Nicole Cordes
Tested-by: Nicole Cordes