Make Jpegli standalone, remove most part of libjxl code #16

Job	Run time
.deb packages / ubuntu:22.04	54s
.deb packages / ubuntu:20.04	1m 3s
Release linux x86_64 static	2m 52s
.deb packages / debian:bullseye	1m 11s
.deb packages / debian:bookworm	1m 10s
.deb packages / debian:trixie	55s
.deb packages / debian:sid	57s
Windows Build (vcpkg / x86-windows-static)	6m 37s
Windows Build (vcpkg / x64-windows-static)	6m 15s
Windows Build (vcpkg / x86-windows)	4m 57s
Windows Build (vcpkg / x64-windows)	4m 20s
	31m 11s

Provide feedback