overlay: OBS control window via WebSocket API (#773)

## Link to GitHub Issue or related Pull Request, if one exists
n/a

## Description of change
Adds an overlay window widget for controlling OBS over WebSocket.

Add new lines to the FPS widget that shows recording / streaming timers.

Show notifications for major state changes (stream started/stopped,
recording started/paused/resumed/stopped)

## Testing

src/spice2x/launcher/options.h

@@ -305,7 +305,12 @@ namespace launcher {
             DisableHighResTimer,
             EnableICMPHook,
             AutoElevate,
-            CfgForceSoftwareRender
+            CfgForceSoftwareRender,
+            OBSWebSocketEnabled,
+            OBSWebSocketHost,
+            OBSWebSocketPort,
+            OBSWebSocketPassword,
+            OBSWebSocketDebug
         };
 
         enum class OptionsCategory {