[TASK] Streamline Page Argument merge strategies

PageArguments are fetched and added on top of PSR-7 request
queryParams right after they are validated from the PageRouter.

They are also re-populated after config.defaultGetVars has
modified global state.

But they do not need to be set to TSFE again within the
the PageArgumentValidator middleware.

Resolves: #86483
Releases: master
Change-Id: I03df4223832845038d4207417cfcab7cbcc687dc
Reviewed-on: https://review.typo3.org/58507


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>