Selection merge workflow for Points

Task to confirm selection merge workflow works for Points, MultiPoints and points in a GeometryCollection.

1. Select features using a range of selection tools; and refine with table view if needed
2. Right click and run merge operation
3. Open merge view to confirm what is to be done; present a list of features to be merged and allow them to be included / excluded

In particular the selection of a point is difficult, the existing bbox tool allows selection (with shift to drag around additional features). The merge tool itself offers similar functionality.