iTwin
implementing schema changeinfo, changeoptions, etc...
It seems the only time we need that SchemaContextEditor in the SchemaEditChangeBase implementations is to add the edit info (and to call changeCancelled.
I think it would be cleaner if the adding to a context is done in the context since it also manages the changes. That would prevent a reference to the Editor in the ChangeInfo objects (which would be purely informative) and move the majority of change-tracking and reverting logic to the context only.
After changes became edits, we need to update a few more places (file names, properties and methods especially in ChangeInfo/Options) :)
This PR should remain open for now as it contains unfinished Schema Editing changes that we will most likely need in the future. This code should be reviewed for necessary changes, current conflicts resolved, and get buy-in from PR reviewers.