Canvas interaction with toolbar buttons (zoom/pan/reset/select)

[threefold3]

Goal

Implement an option to add a toolbar with default buttons to allow users to
interact with a plot.

Proposed UI

• Zoom in (wx::ArtId::ZoomIn icon): click on Button
• Zoom out (wx::ArtId::ZoomOut icon): click on Button
• Zoom to region (wx::ArtId::Find icon): click on Button, then left
  click + drag to select the region to which to zoom
• Pan (wx::ArtId::Move icon): click on the ToggleButton, then left
  click + drag
• Reset (wx::ArtId::Home icon): click on the Button

Prior art

TODO: research existing defaults in other plotting libraries so that our
defaults feel natural for users.