[3.0] [WIP] Remove *.class parameters in bundles

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | will fix #11881
| License       | MIT
| Doc PR        | none

Remove the *.class parameters in all bundle settings.

see: https://github.com/symfony/symfony/issues/11881
this is wrong currently, because the ``validator.class`` parameter was replaced by the DI extension. You need to update the extension to set the service class instead now