This PR merges the stubs fromhttps://github.com/microsoft/python-type-stubs/tree/main/stubs/networkx so that removing them from there produce no regression for Pylance users.

I didn't make much effort in completing annotations other than validating what I was copying over.
In doing that I did find quite a handful of incorrect annotations though.

I've already started a few PRs, and will create more that have specific scopes to make it easier to review these changes in chunks. (and will serve as self-review for this big PR). Until then, I'll keep this as draft.