tests: Mock libfeedback

Copied from libfeedback as of 2e081602f627505e566cc0bdb6cd96c7642d8b65
and adjusted for our mocking needs.

The mocked library will be LD_PRELOADED for the moment,
but further changes to the build should allow us to simply link
to it in the future.

tests/mock/lfb/lfb-enums.h

@@ -0,0 +1,24 @@
+
+/* This file is generated by glib-mkenums, do not modify it. This code is licensed under the same license as the containing project. Note that it links to GLib, so must comply with the LGPL linking clauses. */
+
+#pragma once
+
+            #include <glib-object.h>
+
+
+            G_BEGIN_DECLS
+
+/* enumerations from "lfb-event.h" */
+
+
+GType lfb_event_state_get_type (void);
+#define LFB_TYPE_EVENT_STATE (lfb_event_state_get_type())
+
+
+GType lfb_event_end_reason_get_type (void);
+#define LFB_TYPE_EVENT_END_REASON (lfb_event_end_reason_get_type())
+
+G_END_DECLS
+
+/* Generated data ends here */
+