Add commonCropName field to SeedLot/InventoryLot

SeedLots/InventoryLots are generated from Germplasm operations, therefore should be associated with a crop.

Add commonCropName field to SeedLot/InventoryLot

Potentially SeedLots can be across Crop, not sure of the use case. but better to make the field nullable.

[guydavenport]

I am the ghost :)