[BUGFIX] Template Editor: add min-width to t3editor

Resolves: #71371
Releases: master
Change-Id: Ifc4d9216aed7d5d7b790751ed89d58435bdefd07
Reviewed-on: https://review.typo3.org/44580


Reviewed-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>