Nomads intel probe timers need refactoring

Currently there is only a global timer which doesnt make that much sense, and there instead should be a timer per unit with the ability, and it should set availableNow to 0/1, disabling or enabling the local button as well.

Start by locating the global Nomads intel probe timer, the per-unit probe logic, and the local button state that uses availableNow. The work is done when each unit has its own timer, availableNow is set to 0 or 1 appropriately, and the corresponding local button is disabled or enabled.

Written by the indexing model from the issue text.