[NEW FEATURE] Ensure user will see full Canvas or are aware of hidden parts of the canvas when opening a Microscope.JSON file

[strambc]

Is your feature request related to a problem? Please describe.
When users open an existing Microscope they might not be aware of the parts of the microscope that are hidden to the right

Describe the solution you'd like
Two possible solutions:

1. Show with arrows or labels that there are parts of the Canvas that are not visible
2. Open the Canvas by default in full zoomed out view

[strambc]

This is related to the #421