hasSelection & layerHasSelectionProperty - remove duplicate implementation #397
Description
class org.locationtech.udig.tool.select.internal.LayerHasSelectionProperty (Property hasSelection) duplicates functionality from org.locationtech.udig.project.ui.operations.LayerSelectionProperty (layerHasSelectionProperty)
In addition to this a namespace (e.g. org.locationtech.udig.ui.objectProperty as prefix) should be used to avoid conflicts with other properties