multimedia/quodlibet: Update to 3.6.2

• Move to gtk3 and gstreamer-1.0 [1]
• Add dependencies on musicbrainzngs, notification-daemon, libsoup, libwebkit2gtk-4.0, pygobject3 [1]
• Remove gconf, python, musepack from USE_GSTREAMER (not in gstreamer 1.0)
• Change name of gstreamer mp3 plugin from mp3 to mad (per gstreamer 1.0 ports)
• Add LICENSE_FILE, and general port tidy-up
• Update WWW link to new project site
• Remove pkg-message regarding adding new plugins, as they are now bundled [1]
  
  [1] https://quodlibet.readthedocs.org/en/latest/packaging.html

Changes this release:

https://quodlibet.readthedocs.org/en/latest/changelog.html

PR: 208988
Reviewed by: mat (mentor)
Approved by: johnson.peter@gmail.com (maintainer timeout), adamw (mentor)
Differential Revision: https://reviews.freebsd.org/D6604