www/midori: Back to pool

The midori project has not been connected to the xfce project for
some time. So also remove the xfce category.

While here update WWW to pint to the new maintainers' website.

For rationale and further info see:

Mailing list thread:
  https://lists.freebsd.org/archives/freebsd-xfce/2023-October/000503.html

Archived repo with botched update attempt:
  https://github.com/madpilot78/ports-midori-overlay