GetUnitId and GetUnitKey (for data table)

there is a function/native called UnitFromId(int) to get a unit from a index but there is no function to get the index of a unit.
so i made this small system to get the index from a unit.

i also add a small addon for data tables so you can use it like wc3 hash tables (save as key of (triggering unit)).

Note: it uses UnitUserData (Slot 10)

but there is a sc2 intern bug.
units that are not placed in the terrain editior get no index.
i try to fix it as soon as possible