rsx/overlays: Reimplement message queue

[kd-11]

Bunch of changes, both functional and aesthetic.

1. I had some code lying around for rounded rects, I made the overlay messages use this as well now before adding to other parts.
2. Implement message stacking. Don't display the same message multiple times.
3. Add both top pinned and bottom pinned notifications. Each set can display upto 3 simultaneous notifications. Notifications can be multiline as well without overlap issues.
4. Removes the shader compilation notification and replaces it with a notification message.
5. Add support for animated icons to the overlay system.
6. Add an animated icon to the shader compilation notification instead of the janky dots. Animation was done in gimp and exported and there is full support for sprite animation now in the UI. If someone has a better sprite-set, I can use it instead.
7. Messages have a seperate fade-in and fade-out animation as well. Makes messages spawning in less janky.

Some screenshots:

Known issues:

• Rounded edges with small radius look a bit janky due to some issues with shading. The meshes are generated correctly though, it's a polygon filling issue afaict.

Fixes #13270

[kd-11]

Linux build is borked, I'll have to check it tomorrow.

[Megamouse]

It's odd that the upper margin of the text is always bigger.
I noticed this in my settings branch. I don't remember if i just added some offset or fixed it otherwise though.