Screens of define/ insepct type redesign

[annedino4]

See #81, I have designed some symbols for typedef UI buttons, however, it can seem ambiguous to the students/ redundant in the UI.

To solve the issues, I redesigned the page with better visual hierarchy (figma file):

We should still disable "add parameters" for beginners.

[georgefst]

We now render and edit typedefs on the canvas (#863, #968 etc.).