Load test fully working

* Merged postcode and Name into single "Key" tag in DwellingGroup tag
* Removed DwellingGroupTestFactory and replaced with DummyDwellingGroups and DwellingGroupImpls as required
* Unified getKey across DwellingGroup implementations to use postcode + location, this necessitated all DwellingGroup impls in tests to have a postcode set
* Enhanced Load test
* Split up setUp of RouteBuilderPanelModelTest to allow loadTest to have no routes loaded
* Made DwellinGGroupImpl and Postcode Impl public
* Added force parameter to MapPalnelModel and exposed updateImage model to MapViewGenerator
* Added force parameter to display method of MapPanelModel
* Added force parameter to setSelectedBoundedArea method of RouteBuilderPanelModel