New sort functions for multiplayer roles selection

[Sharknado]

Because the listings of vehicles and aircraft are massive when selecting a role on multiplayer servers it would be nice to have a drop down filter in the menu to select and show only the airframes or vehicles that have been filtered to and filter out any others. so for example if i want to fly the F-18, i would be able to select the F-18 from the drop down filter and the list would only populate the f-18 spawn points and not anything else in the list.