Favicon PNG encoder in WASM instead of JS

[bwdq]

I have many tabs and TSM lags my browser quite a lot. I profiled Firefox and found the culprit was UPNG js PNG encoder found in ./docs/compressor/browser-image-compression.js

I have 1 CPU core with 100% utilization encoding PNG's.

This is my proof of concept WASM PNG encoder shim.

Let me know what I can do to make this mergeable.