/!\ this commit is huge. Jp is temporarily not working with `dbus` bridge /!\
This patch implements the port of jp to asyncio, so it is now correctly using the bridge
asynchronously, and it can be used with bridges like `pb`. This also simplify the code,
notably for things which were previously implemented with many callbacks (like pagination
with RSM).
During the process, some behaviours have been modified/fixed, in jp and backends, check
diff for details.
76aadbb3fb