Add bitrate auto-adjustment toggle and reset button

This change adds a 'Use Default' button next to the bitrate slider that resets the bitrate to the default value for the current resolution/FPS. It also implements an autoAdjustBitrate setting that controls whether the bitrate is automatically updated when resolution/FPS/YUV444 settings change.

- When the user manually adjusts the bitrate slider, autoAdjustBitrate is set to false
- When the user clicks the 'Use Default' button, autoAdjustBitrate is set to true
- Bitrate is only updated automatically when settings change if autoAdjustBitrate is true

app/settings/streamingpreferences.cpp

@@ -16,6 +16,7 @@
 #define SER_FPS "fps"
 #define SER_BITRATE "bitrate"
 #define SER_UNLOCK_BITRATE "unlockbitrate"
+#define SER_AUTOADJUSTBITRATE "autoadjustbitrate"
 #define SER_FULLSCREEN "fullscreen"
 #define SER_VSYNC "vsync"
 #define SER_GAMEOPTS "gameopts"
@@ -122,6 +123,7 @@ void StreamingPreferences::reload()
     enableYUV444 = settings.value(SER_YUV444, false).toBool();
     bitrateKbps = settings.value(SER_BITRATE, getDefaultBitrate(width, height, fps, enableYUV444)).toInt();
     unlockBitrate = settings.value(SER_UNLOCK_BITRATE, false).toBool();
+    autoAdjustBitrate = settings.value(SER_AUTOADJUSTBITRATE, true).toBool();
     enableVsync = settings.value(SER_VSYNC, true).toBool();
     gameOptimizations = settings.value(SER_GAMEOPTS, true).toBool();
     playAudioOnHost = settings.value(SER_HOSTAUDIO, false).toBool();
@@ -312,6 +314,7 @@ void StreamingPreferences::save()
     settings.setValue(SER_FPS, fps);
     settings.setValue(SER_BITRATE, bitrateKbps);
     settings.setValue(SER_UNLOCK_BITRATE, unlockBitrate);
+    settings.setValue(SER_AUTOADJUSTBITRATE, autoAdjustBitrate);
     settings.setValue(SER_VSYNC, enableVsync);
     settings.setValue(SER_GAMEOPTS, gameOptimizations);
     settings.setValue(SER_HOSTAUDIO, playAudioOnHost);