Make current driver compatible with the OP_MSG protocol (#137)

* Make current driver compatible with the OP_MSG protocol

Starting with mongodb v6 the OP_MSG protocol is the only accepted message protocol that is accepted by mongodb.
All prior protocols are deprecated. This commit implements the protocol keeping the current client facing API intact.

See:
https://github.com/mongodb/specifications/blob/master/source/message/OP_MSG.rst
https://medium.com/@asayechemeda/communicating-with-mongodb-using-tcp-sockets-521490f981f

Co-authored-by: Doro Rose <doroerose@gmail.com>

Author: kfiz