Scrawl-canvas v8 - Canvas test 062

Group and ungroup entitys; create a bespoke drag-drop UX

Use drag action to create a selection group.
Selection group is draggable after creation.
Click outside the selection group to remove it.

Test purpose

Create a set of Block entitys spread randomly across the canvas, in their own group
Create an addition Block, in its own group, to handle box selection and movement; make the block sensitive to mouse hover (and touch) actions
Create functions to handle mouse down, move and up actions

If no selection, or mouse down occurs outside selection, create a new selection as user drags the cursor across the canvas
If mouse down occurs inside the selection, move the selection and its box as user drags the cursor across the canvas

When selected, check that those entitys are fully opaque and animated (by delta roll)
When not selected, check that those entitys are translucent and stationary
When user hovers mouse over selection, check that the selection box border changes and the cursor changes to a grab hand

Touch test: not required