[TASK] Move BitSet class into different namespace

The BitSet class has been put into a DataStructure
namespace although the core puts classes of these
kind into a Type namespace. Therefore, the class
has been moved.

Releases: master
Resolves: #88596
Change-Id: I18385a5c761e002f36bc33dcaeeb26ce7f6d187e
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61098


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Alexander Schnitzler <typo3@alexanderschnitzler.de>