feat: integrate real Carla host with JACK support and add plugin abstraction layer

client/src/carla_host.h

@@ -5,6 +5,9 @@
 
 /* All functions return -1 on error, 0 on success (except carla_load which returns 0 on success and sets *out_id) */
 
+int carla_init_jack(void);
+void carla_cleanup_jack(void);
+
 int carla_load(const char *binary, const char *plugin_id, int *out_id);
 int carla_unload(int id);
 int carla_connect(int id, const char *port_name, const char *looper_port);