unzip + zstd support

Fork of http://www.info-zip.org/

Added support for zstd compression method.

The zip 6.3 format has official support for zstd.

https://en.wikipedia.org/wiki/ZIP_(file_format)

www.zstd.net

linux build

option1: using cmake

cmake .
make
./unzip -v

option2: using make

make -f unix/Makefile generic_zstd
./unzip -v