Update SDL3, add SDL3_image

[isage]

Note: sdl image no longer requires libpng/libjpeg and uses stb_image to load images and tiny_jpeg / miniz to save jpeg/png.

[isage]

Lemme do some tests of stb_image vs libpng/libjpeg first

[isage]

libpng / libjpeg:

10 JPEGS TOOK: 5128644 msec
10 PNGS TOOK: 4314961 msec

10 JPEGS TOOK: 5130477 msec
10 PNGS TOOK: 4313254 msec

10 JPEGS TOOK: 5132565 msec
10 PNGS TOOK: 4324340 msec


stb_image:

10 JPEGS TOOK: 6058681 msec
10 PNGS TOOK: 4984479 msec

10 JPEGS TOOK: 6055964 msec
10 PNGS TOOK: 4975862 msec

10 JPEGS TOOK: 6053126 msec
10 PNGS TOOK: 4979222 msec

stb_image is slower, so let's switch back to libpng/libjpeg
(it adds around 340kb vs stb_image, but we can live with that_