[TASK] Deprecate cliKeys logic and cli_dispatch.phpsh entrypoint

The way of calling CLI scripts from within TYPO3 via the "cliKeys"
functionality and the typo3/cli_dispatch.phpsh entrypoint have been
superseded by the new Symfony Console integration.

All code related to this functionality has been marked as deprecated.

Calling the CliRequestHandler (which is the main entry point for the
cli_dispatch.phpsh) will trigger a deprecation message warning.

Resolves: #80468
Releases: master
Change-Id: Ib72ab93bee27421163c9117ebedcc0e97e17d41e
Reviewed-on: https://review.typo3.org/52173


Reviewed-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: Frank Nägler <frank.naegler@typo3.org>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>