Changes:
- Add a VehicleType property to VehicleSpec
- Update vehicles.xml to include the type property; currently same as the name
- VehicleConfig parses the new type property and convert to VehicleType
- Created a VehicleFactory that centralises Vehicle creation
- Generantename method moved from Vehicle to VehicleFactory
- Update the creators of Vehcile to use the new factory class

Part of #854

Changes:
- VehicleFactory passed the VehicleSpec to constructor
- Vehicle & subclasses take VehicleSpec as argument
- Unit test use new Vehicle constructor
- Remove Vehicle.getDescription method that uses the vehicle type

Part of #854

Changes:
- Replace property vehicleTypeString with specName in Vehicle which is the name of the seed VehicleSpecification
- UI & console classes update to show Vehicle specification name instead of type
- SVG Vehicle images now selected based on the VehicleType value instead of the type string
- Updated to svg image mapping to aligned with LUV
- Reworked the SVGMapUtil test to use the new approach
- Only one VehicleGood object created per VehicleType in the GoodsUtil class
- VehicleGood counts settlement vehicles based on the VehicleType not the spec
- Maintenance scope based on VehicleType value at base; update parts.xml to align to luv
- Rover class add extra maintenance scoep for "rover"
- Dropped MockVehicle class as it did not follow the VehcileSpecification constructor pattern
- Reworked TestContaiment to use the AbstractMarsSimUnitTest to provided required Units
- AbstractMarsSimUnitTest registers new Garage building with the BuildingManager

Part of #854

Changes:
- VehicleSpec has an optional base image property used in SVG drawing; default is the VehicleType
- Vehicle base images used in all SVG Util lookup for drawing in General tab of Vehicle
- VehicleMapLayer uses new baseImage property for rendering
- SVG test updated
- VehicleTableModel uses the vehicle specification name instead of the type
- General vehicle tab show vehicle specification as well as type
- Add a new "Long Explorer" to vehicles.xml giving a explorer with a longer range
- Alpha Base creates "Long Explorer" vehicles
- Created a new SVG image for the long explorer, matches existing dimensions to reuse overlays
- svg image mappings added for new vehicle spec
- Settlement vehicle console command displays vehicle specification instead of type

Part of #854