Contract Builder: Custom Dropship Extraction Node

[CWolfs]

A custom Dropship Extraction Node is required. Reuse of the existing vanilla DropshipExtractionNode won't be appropriate due to how it references the vanilla DropshipLandingSpotGameLogic. Since MC uses a CustomDropshipLandingSpotLogic (aka: DropshipLandingSpot Node) a custom Node is required.

The main requirements for this work are:

• Must handle the multi-dropship feature that the CustomDropshipLandingSpot provides
• Must still support ExtractionOverrides that come from the contract files / ContractOverrides