[New Feature] Placing factory rally points without holding Alt

[Rampastring]

Description:

Tiberian Sun allows you to place rally points for factories. However, the vanilla game requires you to hold Alt while placing rally points, because of which most players were never aware of this functionality until CnCNet TS came along and changed the game to allow setting rally points like RA2, without needing you to hold any special keys.

What makes this a bit trickier for TS is Mobile War Factories: being able to place rally points without holding Alt prevents the player from undeploying deployed Mobile War Factories. Unless a patch is made to allow undeploying them by holding Alt instead.

Possible Implementation:

CnCNet TS-patches implementation: https://github.com/CnCNet/ts-patches/blob/master/src/factory_rallypoints.asm