Improve WebP settings

[jonnyawsom3]

Increases lossless encoding speed tenfold and improves lossy quality while halving filesizes.
Last commit only makes it 2x faster but also 20% smaller, to avoid edge cases where the image was larger.
Rebase of #17 due to messy communication and commit history.

To fix #20, the JPEG and PNG changes need to be implemented within FrooxEngine, which is being discussed in Yellow-Dog-Man/Resonite-Issues#4953 and my comment in Yellow-Dog-Man/Resonite-Issues#874 (comment).

[jonnyawsom3]

Copied from Yellow-Dog-Man/Resonite-Issues#874 (comment)

Here are current PNG saving times compared to my recommendations. 15x faster and only 15% larger.

Seconds	Old	New	Speed	Size
1080p	7.77	0.53	14.66x	+10%
1440p	13.67	0.91	15.02x	+10%
2160p	31.21	1.92	16.26x	+14%
4320p	126.4	7.63	16.56x	+20%

JPEG results. Half the size at the same quality, still under half a second.

2160p	Seconds	Size (MB)	SSIMU2 (Quality)
Old	0.26	3.24	87.19
New	0.46	1.31	86.98

Unfortunately testing WebP in-game requires recompiling FreeImage, which we couldn't do, but here are external results.
Different resolutions use different images, so speed and size will vary, but smaller on average and 10x faster.

Seconds	Old	New	Speed	Size
1080p	1.47	0.145	10.14x	-3.4%
1440p	2.15	0.26	8.27x	+1.2%
2160p	5.9	0.6	9.84x	-0.3%
4320p	28.5	2.47	11.54x	-2.2%

[j4lc]

@jonnyawsom3 Hey, your PR looks good, I'd merge this as-is, but the workflows need to pass.

There was a slight issue in the configuration which was fixed in the latest main. Could you please rebase your branch onto it, so everything can run?
Thanks!

[jonnyawsom3]

Hopefully that fixes it, though there's also the changes in #20 to do in FrooxEngine too. Thanks for taking a look at it!

[jonnyawsom3]

Anything left to do my side?

[j4lc]

Nope, that's perfect. Sorry for the delays, I'm gonna test this now.