Websocket Stream Stats & Robustness Improvements (#605)

* wip support for a stats overlay

* WIP adding stream stats. But.... eeeh. Corporate.

* kbits over mbytes

* A ton more tweaks:

- Increased thread priority for streaming to reduce "stutter/slow" issues
- revised client side URL creation order to prevent the possibility of repeat-identical URL's
- Improved overlay to only be visible on mouseover, and fully centered in the screen

* wpiformat on js

photon-server/src/main/java/org/photonvision/server/CameraSocketHandler.java

@@ -51,7 +51,7 @@ public class CameraSocketHandler {
 
     private CameraSocketHandler() {
         cameraBroadcastThread = new Thread(this::broadcastFramesTask);
-        cameraBroadcastThread.setPriority(2); // fairly low priority
+        cameraBroadcastThread.setPriority(Thread.MAX_PRIORITY - 3); // fairly high priority
         cameraBroadcastThread.start();
     }