Summary: This makes the user's role (owner/editor/viewer) available in ActiveDoc methods. No use of that information is made yet, other than to log it. The bulk of the diff is getting a handle on the various ways the methods can be called, and systematizing it a bit more. In passing, access control is added to broadcasts of document changes, so users who no longer have access to a document do not receive changes if they still have the document open.
Test Plan: existing tests pass; test for broadcast access control added
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2599
Summary: This moves enough server material into core to run a home server. The data engine is not yet incorporated (though in manual testing it works when ported).
Test Plan: existing tests pass
Reviewers: dsagal
Reviewed By: dsagal
Differential Revision: https://phab.getgrist.com/D2552
