[InfoHud] Add current input size to the playback index

Currently, the playback index only shows the current tick of the recording.
Now a second variable is added to show the size of the recording with the format 0/0,
with the second one being the size.

To get the size, I use PlaybackController#size()-1 as the index is always one smaller than the size.
And to not get negative numbers when no inputs are present, I use Math.max(size, 0)

Author: ScribbleTAS

src/main/java/com/minecrafttas/tasmod/gui/InfoHud.java

@@ -454,7 +454,8 @@ public boolean checkInit() {
 					+ "_visible")), Boolean.parseBoolean(configuration.getProperty(title + "_rect")), () -> {
 						if (Minecraft.getMinecraft().currentScreen == this)
 							return "PlaybackIndex";
-						return Long.toString(TASmodClient.controller.index());
+
+						return String.format("%s/%s", TASmodClient.controller.index(), Math.max(TASmodClient.controller.size() - 1, 0L));
 					}));
 
 			y = height - 14;