Move Plasma Firewall from KDE Review per the request of it's maintainers.

Also, transfer Plasma Firewall from the Network group to the Plasma group.

Note to Plasma developers: Please ensure you specify the correct group in the beginning, projects are meant to minimize their moves between groups as much as possible.
In this instance the plasma/ group is intended both for projects that are part of the Plasma release unit, as well as Playground and Extragear projects that are related to Plasma.

CCMAIL: kde-core-devel@kde.org
CCMAIL: plasma-devel@kde.org

Ref T14012