Add drag and drop feature to static weapons, something similar to drag and drop unconscious bodies.

This can help make life easier when:

• turning an AA static weapon around when plane flies over in the opposite direction
• adjust static MG position near a window inside a building without having to work with disassembling/assembling it back
• it is not intuitive for new players to understand that they need to look in the same direction they want the static weapon to be pointed at while assembling it