Remove the Graphql::GIDExpectedType cop (enforces expected_type param in object_from_id calls)

The Graphql/GIDExpectedType cop enforces that we pass an expected_type param when calling Gitlab.object_from_id, but our Global IDs validate that the object resolved from a Global ID matches the model which does the same check as the :expected_type param.

We should:

• Remove the cop
• Probably remove most (or all?) of the uses of expected_type: in our codebase.