Provide concrete classes that will be instantiated multiple times
with different options. E.g. provide an RssWidget implementation, that
can be used multiple times with different rss feed urls.

Split configuration for UI (title, icon, …) from concrete
implementation. A new WidgetConfigurationInterface is in place and used.

Resolves: #90660
Resolves: #90852
Releases: master
Change-Id: I194615164b7d3d1cbd63751ddfd1f66f71db64cf
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63563


Tested-by: Koen Wouters <koen.wouters@maxserv.com>
Tested-by: Richard Haeser <richard@maxserv.com>
Tested-by: Riny van Tiggelen <info@online-gamer.nl>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Susanne Moog <look@susi.dev>
Reviewed-by: Richard Haeser <richard@maxserv.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Susanne Moog <look@susi.dev>