[FEATURE] Add placeholder argument to VH for Textarea and Textfield

Change-Id: I8c4cc22e10ce2991f48c32b7934bf01346f8aecf
Resolves: #45960
Releases: 6.2
Reviewed-on: https://review.typo3.org/20281
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Helmut Hummel
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind