collection-level count methods now accept filters

[dill0wn]

Rather than rely on a cursor for filtered counts, let the collection's count method use pymongo.collection.count_documents(filter, ...) under the hood so it's possible to get a count with Collection.m.count({'some': 'filter'})

I have only updated ming.Session.count which is accessible from Document.m.count(...). There are a few other def count wrappers/implementations that might also be helpful to use this.

Additionally, pymongo itself has deprecated db.collection.find().count() and prefer count_documents(). See https://pymongo.readthedocs.io/en/4.14.1/common-issues.html#deprecationwarning-count-is-deprecated

With that in mind, maybe a more thorough audit is in order.

[brondsem]

I am not sure if we need Document.m.count(...) since we already have Document.m.find(..).count()

Regarding count_documents, Ming's count() method is using that. I don't think we're calling the pymongo deprecated count() anywhere (although I could be wrong)

[dill0wn]

That's fair. Ming is an abstraction after all. And the two are functionally (and performantly) roughly equivalent AFAICT. Maybe not needed?