To Sphere Tool Todo

• We should add To Sphere to the toolbar
• Click and drag to increase amount
• The tool should have a way to change the center point via a manipulator.

Note: The initial center point should follow whatever is set in the Pivot dropdown. If the user wants to use the 3D Cursor as a center point, they can select the 3D CUrsor from here. When the user has engaged the To Sphere tool, we display a redo-gizmo which lets users interactively adjust the center point and see the result update live.