www/wget2: add port: File and recursive website downloader

    GNU Wget2 is the successor of GNU Wget, a file and recursive website
    downloader.

    Designed and written from scratch it wraps around libwget, that
    provides the basic functions needed by a web client.

    Wget2 works multi-threaded and uses many features to allow fast
    operation.

    In many cases Wget2 downloads much faster than Wget1.x due to HTTP2,
    HTTP compression, parallel connections and use of If-Modified-Since
    HTTP header.

    WWW: https://gitlab.com/gnuwget/wget2

Unlike wget, this was placed into www category as it does no longer
support ftp.