Support transformation between D-Bus errors and exceptions.

[poncovka]

Exceptions can be registered with decorators, raised in a remote method and recreated after return from the remote call.

[poncovka]

It's been a while since we've switched from pydbus to dasbus (https://github.com/rhinstaller/dasbus). The library is stable and well tested, so it could make other people happy. Here is a link to the main differences: https://dasbus.readthedocs.io/en/latest/pydbus.html