Add fetchcode support for luarocks

[TG1999]

pkg:luarocks/luasocket@3.1.0-1 -> https://luarocks.org/luasocket-3.1.0-1.src.rock

pkg:luarocks/hisham/luafilesystem@1.8.0-1 -> https://luarocks.org/luafilesystem-1.8.0-1.src.rock

[TG1999]

Done in package-url/packageurl-python#199