Make `JobParameters` stricter in DiracX

In https://github.com/DIRACGrid/diracx/pull/626, we made the `JobParameters` pydantic model very flexible to allow any undocumented parameter to go through, but as discussed in the latest Bild Meeting, we actually want to document them and thus have a stricter model that take all of them into account.

Extensions should be able to easily extend the model in they have additional job parameters to support.

It involves going through DIRAC and streamline the job parameters (remove old and unused ones, merge the ones that are similar...).