Allow flagged SF civilians to queue for battlefields

Allow civilians which are flagged special forces to join a group and queue for battlefields with their respectively flagged faction.

This allows people who may choose to go civilian to participate in the battlefields and get tokens, just like invasions. This may increase participation by opening them to a wider pool of players. In addition, it will help allow more battlefields to run as people can "fill" spots as needed - it is rare to have the exact amount of people on each side queuing.

More pvp, more battlefields. Reflects consistent implementation, same as the GCW invasions work.

Civilian should be an attractive proposition to pvpers who want more action and can fight both sides, with the disadvantage of not having any ranked rewards available. In a server with smaller population, this is much more important as the current situation simply means battlefields are run less, with the same people every time. PvP is a great part of the game. More pvp often brings about even more pvp as more people play and have a go and enjoy it.