Introduced a `--use-session-bus` flag to optionally use the D-Bus
session bus instead of the system bus. This allows better flexibility
for local testing and development scenarios without requiring
system-level changes. Updated related classes and functions to respect
the new flag.
Introduce the main daemon class for revpi-middleware with methods for
initialization, configuration, DBus handling, and a mainloop. This
implementation includes support for configuration reloads, log rotation,
and proper thread management for DBus operations.
