Add --require-audio

By default, scrcpy mirrors only the video when audio capture fails on
the device. Add an option to force scrcpy to fail if audio is enabled
but does not work.

PR #3757 <https://github.com/Genymobile/scrcpy/pull/3757>

app/src/demuxer.h

@@ -27,8 +27,15 @@ struct sc_demuxer {
     void *cbs_userdata;
 };
 
+enum sc_demuxer_status {
+    SC_DEMUXER_STATUS_EOS,
+    SC_DEMUXER_STATUS_DISABLED,
+    SC_DEMUXER_STATUS_ERROR,
+};
+
 struct sc_demuxer_callbacks {
-    void (*on_ended)(struct sc_demuxer *demuxer, bool eos, void *userdata);
+    void (*on_ended)(struct sc_demuxer *demuxer, enum sc_demuxer_status,
+                     void *userdata);
 };
 
 // The name must be statically allocated (e.g. a string literal)