Fix HUD rerenders on Hytale 0.5.1

[Janiel777]

HyUI 0.9.7 - Hytale 0.5.1 HUD rerender follow-up

While testing v0.9.7 - Complete Build Change, 0.5.1 support? against Hytale 0.5.1, I found one remaining HUD-specific runtime issue.

The original CustomUIHud(PlayerRef) crash is fixed by the 0.5.1 changes, and custom pages still render and interact correctly.

The remaining issue is that custom HUDs render their first frame, but later updates do not visually refresh on the client.

Runtime comparison

Before this fix

The HUD is created and the first frame is visible, but the countdown/progress text stays frozen. The game logic continues running server-side.

After this fix

With commit 1cc546b, the same HUD flow refreshes normally after the initial render.

What caused it

This seems to come from the new native HudManager behavior in Hytale 0.5.1.

The new API stores custom HUDs by key. In HudManager.addCustomHud(...), if the HUD currently registered for that key is the same object instance, the method returns early.

So the flow became:

HyUIHud.update(builder)
  -> refreshOrRerender(true, false)
  -> MultiHudWrapper.setCustomHud(player, playerRef, name, this)
  -> HudManager.addCustomHud(playerRef, this)
  -> same key + same HyUIHud instance
  -> early return, no new CustomHud packet sent

That means the first render works, but later full rerenders can be skipped before any updated HUD commands reach the client.

Fixes #39