Fix units restarting orders when tasked to attack/gather/repair/heal same unit.

FSM states would be left/re-entered, resetting the timer, which did not happen pre rP22023 and is undesirable in general.
This explicitly checks for a few cases where timers are relevant.

Essentially a Patch by: Freagarach

Differential Revision: https://code.wildfiregames.com/D3531