Fixes to type for _id in MongoDB documents return with $db.f

[danswann]

• Removes boolean literal false as a valid type for _id, as attempting to insert a new document with _id:false produces the following error:
  :::TRUST COMMUNICATION::: can't have multiple _id fields in one document (2)

[danswann]

Tested that all MongoPrimitve values other than null and false work as _ids, so the MongoId type should be 100% accurate to the game environment now.

[samualtnorman]

oh woops I think we both tried to work on this at the same time

[danswann]

I can rebase my exclusion of false on your stuff.

[samualtnorman]

I can rebase my exclusion of false on your stuff.

yeah please, ty

[danswann]

Rebased the false stuff, and also brought parity to MongoQueryId cuz that seems to work in game, i.e.:

#db.f({_id:{$oid:"12345"}});