Switch to Motor for MongoDB Async Conncections

[WMRamadan]

Initial checklist

• [X] I read the support docs
• [X] I read the contributing guide
• [X] I agree to follow the code of conduct
• [X] I searched issues and couldn’t find anything (or linked relevant results below)

Problem

PyMongo does not support async MongoDB connections.

Solution

Switch to Motor which supports MongoDB async connections.

Alternatives

None.