custom shader: added cursor style and visibility uniforms

[ClearAspect]

Fixes: #9416

Specifically: iCurrentCursorStyle iPreviousCursorStyle iCurrentCursorVisible iPreviousCursorVisible

Visibility calculated and updated independently from the typical cursor uniform updates to preserve cursor style even when not in the viewport or set to be hidden

I used Claude-Code to initially navigate and gauge an understanding of the rendering system. Otherwise I authored the rest of the PR

[ClearAspect]

While I was working on another issue, I just realized I could have also used the surface mailbox to get the cursor style information from the surface renderer state. Seems like that's the better way to do it from my understanding and I'll happily rewrite this.