Add lobby option to disable ping attribution

A phantom player has requested a new lobby option to make pings (attack, move, warning) anonymous.

The original FA user interface did not indicate who sent a ping (alert). The ping source indicator (flashing faction icon) was added in FAF (primarily to combat ping spam). It's worth noting that the FA engine has never truly anonymized ping alerts. Even if the ping source indicator is disabled, a basic UI mod would allow someone to turn it back on (for themselves anyway).

I (Duck_42) will not be implementing this request. If someone else want to do it though, I will integrate it.