[NEOS-1173] Expand MongoDB support to allow generating of pre-defined datasets

[nickzelei]

Mongo Atlas has support for this and it's pretty great. They have a button when you create a new database to optionally seed it with test database/collections.

This is pretty great. If we brought something like this to Neosync, it could be used for any Mongo database.

These could be pre-defined datasets, or pre-defined schemas where we generate the data on the fly (or eventually this + seeding for reproducibility).

_{From SyncLinear.com | NEOS-1173}