Add Clapper deamon subprocess

Daemon is responsible for starting and later watching over spawned "broadwayd" and "remote" app needed for remote playback control. We cannot use systemd n Flatpak, so we make do with running optional background subprocesses.

clapper_src/mainDaemon.js

@@ -0,0 +1,6 @@
+const { Daemon } = imports.clapper_src.daemon;
+
+function main()
+{
+    new Daemon();
+}