lib: introduce WpComponentLoader and remove WpModule

The component loader is a more generic and extensible mechanism
of loading components; modules are one type of component...
The idea is to make scripts and config files also be components,
loaded by plugins that inherit WpComponentLoader

lib/wp/wp.h

@@ -10,6 +10,7 @@
 #define __WIREPLUMBER_WP_H__
 
 #include "client.h"
+#include "component-loader.h"
 #include "configuration.h"
 #include "core.h"
 #include "debug.h"