Fix crash caused by selectable troop cards.

Fix an error message when issue movement orders.

Fix the issue in base game: the order position preview is not consistent with final order when dragging formation on the ground.
Fix the issue in base game: narrowed width of a formation cannot be kept after a movement command.
Added an option to show hotkey hint in free camera mode.
Added an option to decide whether to rotate camera when switching from free camera.

Fix crash when player is dead and switch to agent camera, if 'control ally after death' option is disabled.

In free camera mode, while command UI is open, you can press `E` to stick camera to selected formation.
Press `Alt` while middle-button clicking to target the enemy without interrupting previous movement orders. For example, **let your archers focus shooting while holding position**.
Add option for always giving orders in free camera.
Add slow motion in free camera.
Automatically open ordering UI in free camera.
Automatically switch to free camera in deployment stage.
Remove some default hotkeys to avoid accidental triggering.

Minor changes.