[HttpFoundation] added a way to override the Request class

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #7461, #7453
| License       | MIT
| Doc PR        | symfony/symfony-docs#3021

This is an alternative implementation for #7461.

I've also reverted #7381 and #7390 as these changes are not needed anymore.

Todo:

 - [ ] add some tests