taskchampion integration

In [the last community meeting](https://github.com/GothenburgBitFactory/taskwarrior/discussions/3675) @djmitche mentioned that he was interested in seeing an integration of taskchampion into bugwarrior and I'd be curious for his thoughts on that. There is an effort to create python bindings to taskchampion -- https://github.com/GothenburgBitFactory/taskchampion-py -- and I'm curious if we should be depending on an upstream like that or creating our own bindings for the presumably minimal subset of the API we actually need to use.

My primary concern I hope Dustin can address is about taskchampion's database schema version interoperability. As I understand it, bugwarrior would have taskchampion as a dependency, so breaking changes in taskchampion wouldn't be an issue because we'd be linking against a version of our choosing. However, the user's taskwarrior installation might be linked to a different version of taskchampion and the database might have a different schema. How much interoperability should we expect between different taskchampion versions going forward? I suspect it would be very disruptive to our users if bugwarrior didn't have several years of interoperability with taskwarrior.