Fix drag soft-lock when dragging unconscious mercs

[tais]

Summary

Fixes the intermittent soft-lock / ghosted-merc bug when dragging unconscious mercenaries in tactical combat.

SOLDIERTYPE::IsDragging() defaults to aStopIfConditionNotSatisfied = true, which makes it call CancelDrag() — and reposition the dragged body via EVENT_InternalSetSoldierPosition — whenever the drag condition isn't currently satisfied. That side effect was being triggered from read-only consumers including the pathfinding cost loops in FindBestPath / PlotPath, AP cost queries, movement noise, the drag face icon, and carried weight.

Two consequences in combat:

• Constant cancellation / "ghost" merc. Every UI tick (cursor pathing, AI pathing, reachable scans) re-ran IsDragging(true), which kept cancelling the drag and yanking the body back to tile-center, so the drag never visibly "stuck."
• Soft-lock. Repositioning a soldier from inside FindBestPath mutates gpWorldLevelData while the path search is iterating it. FindBestPath isn't re-entrant — that corrupts the search state and the engine ends up waiting on a move that never completes.

Fix: pass false at the 8 read-only call sites so they only read state. A genuinely-dragging soldier still has the body adjacent, so IsDragging(false) returns TRUE and the drag AP/noise/weight modifiers still apply. Only the spurious "condition not satisfied → cancel + teleport body" branch is removed. The genuine state-changing callers (the move executor at Soldier Control.cpp:11519, the ESC handler at Turn Based Input.cpp:2224) keep the cancelling form.

Touches: PATHAI.cpp ×3, Points.cpp ×2, opplist.cpp, Faces.cpp, Items.cpp. +16/-8 lines. Mechanical one-token edit per site.

Related: commit 3d529400 ("Copy drag info to dummy soldier (1dot13#255)") already patched one symptom of the same IsDragging/pathfinding collision (1-tile location shift on load with A* pathfinding).

Test plan

• Compiles cleanly
• Drag an unconscious merc one or more tiles in turn-based combat with A* pathfinding enabled — drag should hold, body should follow the dragger without snapping back
• Repeat with another merc nearby running AI turns (heavy pathfinding) — no freeze
• Drag still cancels correctly on ESC, on the dragged merc getting up, and when conditions actually become invalid (target moved out of reach, dragger stands up)
• AP cost while dragging is unchanged (drag modifier still applies)