Multi-OS support
This makes Axii handle following scenarios gracefully:
- Multiple OS's or OS versions with the same Axii installation (relevant for fileserver-based homes with varying client OS's)
- OS upgrades -> Axii will detect that it has not been installed for that OS
- Workspaces after OS upgrades -> Axii will detect that a workspace has been built with another OS version
Follow-ups:
- What to do if workspace version does not match?
/cc @pohl