alpha release of fallback target logic gadget..

this gadget provides a toggle to allow units to:

⚪ default
direct attack target lost → do nothing (no new logic)

🟢 move
direct attack target lost → move to last known target position
original direct attack target found → direct attack original target

🔴 fight
direct attack target lost → fight order to last known target position
original direct attack target found → direct attack original target

🟣 attack ground
direct attack target lost → attack ground at last known target position
original direct attack target found → direct attack original target