feat(audio): add an option to disable sound streaming (#3833)

src/config.cpp

@@ -511,6 +511,7 @@ namespace config {
   audio_t audio {
     {},  // audio_sink
     {},  // virtual_sink
+    true,  // stream audio
     true,  // install_steam_drivers
   };
 
@@ -1160,6 +1161,7 @@ namespace config {
 
     string_f(vars, "audio_sink", audio.sink);
     string_f(vars, "virtual_sink", audio.virtual_sink);
+    bool_f(vars, "stream_audio", audio.stream);
     bool_f(vars, "install_steam_audio_drivers", audio.install_steam_drivers);
 
     string_restricted_f(vars, "origin_web_ui_allowed", nvhttp.origin_web_ui_allowed, {"pc"sv, "lan"sv, "wan"sv});