[!!!][TASK] Remove unused csConv parameters

[!!!][TASK] Remove unused csConv parameters

There are several additional parameters that are not used
anymore.

CharsetConverter->entities_to_utf8() - now always
CharsetConverter->utf8_to_numberarray() now always
converts entities, and real UTF-8 characters are returned

Resolves: #74031
Releases: master
Change-Id: I6ee4e74bb9122a2ac8b9843a7026c933d7199381
Reviewed-on: https://review.typo3.org/47004
Reviewed-by: Daniel Maier <dani-maier@gmx.de>
Tested-by: Daniel Maier <dani-maier@gmx.de>
Reviewed-by: Benjamin Kott <info@bk2k.info>
Tested-by: Benjamin Kott <info@bk2k.info>