[TASK] Streamline ext:redirects auto-create chain

Changing the slugs of pages automatically creates
redirects, if ext:redirects is installed and
that feature has not been disabled. Detecting and
handling this has been based on the `slug` value
from the page record.

There are some valid use cases which would benefit
from the one or other good placed event. Another
use case would be to create a redirect with a real
build source path, thus respecting configured site
route enhancers and decorators. Creating multiple
redirects based on different arguments and typeNum
may be another use case.

This change acts as a preparation for upcoming
features. Thus, it changes the passed through
dataset in a way to transport valuable data.
Handling and consuming methods have been adjusted.
Pointing out possible places for events are added,
which makes the need for the changes more obvious.

Resolves: #99188
Releases: main
Change-Id: Id928dc65bca27dc93164290dbdaba5e6723dbebb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76816


Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>