Extend hazard outputs to landslide and liquefaction IMTs

[catarinaquintela]

Some hazard outputs, such as hazard maps and hazard curves, are currently generated only for ground-shaking IMTs. Since these outputs are also relevant for landslides and liquefaction, the hazard output needs to be extended to include these IMTs (e.g., Disp, LiqOccur or LiqProb).

[micheles]

This is harder than I thought since the primary IMTs are special (i.e. stored as gmv_0 and not as PGA) and I wonder if I should just change the storage, plus a layer to support backward-compatibility with old GMFs.