[cnc] fixing mcv crates odds

Currently you cannot disable MCVs coming in crates without also disabling them coming in crates when you have no Construction Yard.
Temporary workaround: setting the odds of all other crates really high in comparison (multiplying by 1,000).

Also, removed level-up crates, and changed crate spawn frequency.

Temporarily disabled AI building of HPAD and FIX since they can't use them, and they don't provide any useful pre-requisites. Slight tweak to GDI tank building.