Implement receiver HID++ connect/disconnect events

Many changes were made here but that was the biggest one.

There's currently a bug where std::system_error: Broken pipe is thrown
after launching the daemon with a receiver connector.

A workaround for this bug is to simply shake the mouse while starting
the daemon. I will investigate this soon.

src/logid/CMakeLists.txt

@@ -27,7 +27,9 @@ add_executable(logid
         backend/hidpp20/Device.cpp
         backend/hidpp20/Error.cpp
         backend/hidpp20/Feature.cpp
+        backend/hidpp20/EssentialFeature.cpp
         backend/hidpp20/features/Root.cpp
+        backend/hidpp20/features/DeviceName.cpp
         backend/dj/Report.cpp
         util/mutex_queue.h)