Add stereoscopic 3D to Top Screen Visuals

Currently sets the water background to a depth of 5 pixels per eye, with bubbles being half of that and all other UI elements sitting on the top without 3D separation. Only negative side-effects include framerate halfing due to render lag (because software rendering). It should also be noted that this pulls the 3D slider float value on it's own from 0x1FF81080 rather than ctrulib due to the absence of this value there (as far as I have found).

Since this PR is purely aesthetic the cons may outweigh the pros for this, but I figured I'd throw it up and see what anyone thinks. If you want to give it a whirl you can either compile it or use the binary [here](https://www.dropbox.com/s/mmyua1xr8h6plmi/boot.3dsx?dl=0). It may be better to wait for hardware rendering because at that point we can render all the elements once in a 3D scene and then from there just render twice in hardware for each eye.