Add support for asyncio

[gitbuda]

Some database queries could be quite long. It would be nice to have an async construct to deal with that in the shortest amount of time from a developer's point of view. Maybe the most effective solution is to expose https://docs.python.org/3/library/asyncio.html (in this repo/package or another one).

[katarinasupe]

Related -> https://github.com/memgraph/gqlalchemy/issues/250