[FEATURE] Add splitChar to noTrimWrap

noTrimWrap constructions with empty parts share syntax with optionSplit.
If this is used in HMENU optionSplit takes precedence. A possibility
to set the splitChar solves the ambiguity.

Change-Id: Ia35603dfca64c5d1c9a0ebdacf316ee373e48560
Resolves: #20793
Releases: 6.1
Reviewed-on: https://review.typo3.org/9428
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Eric Chavaillaz
Tested-by: Eric Chavaillaz
Reviewed-by: Benjamin Mack
Tested-by: Benjamin Mack