change_stream_invalidation.js currently tests the following scenarios:

• When a collection is dropped, we return an "invalidate" entry and close the cursor.
• It is not possible to resume a change stream after a collection drop, even if the invalidation has not been received.

We should extend it to test the following scenarios:

• When a collection is dropped, if there are additional insert/update/delete entries that have not yet been received, the user can read the insert/update/delete entries preceding the invalidate entry.
• It is possible to open a new change stream cursor on a collection that does not exist. When the collection is created, we start seeing oplog entries for that collection.