[HttpFoundation] MongoDbSessionHandler supports auto expiry and auto index creation

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11508
| License       | MIT
| Doc PR        | no

ToDo

 * [x] Fix Tests

Looking for feedback on this early PR.


This adds a config option that disables the PHP GC method call from doing anything,
It also means that the write method sets up the auto expiring index.


Ref: #11508
> If the PHP configuration changes because session lifetimes need to be extended site-wide, this storage layer is still going to delete those records based on the original time.

But only for records that have not had activity, as they will have the new expireAt set based on whatever the maxlifetime may have been changed to.

Not sure how much of an issue this actually is.