Simulator serial tweaks.

[microbit-matt-hillsdon]

• Show the hints and tips entry for sim serial, but on the menu due to lack of space.
• Show the expand/collapse text, but deconflict with the traceback on the sim due to lack of space. We decided this is important to understand that it is the serial area as it's otherwise unlabelled.

[github-actions[bot]]

Preview build will be at https://review-python-editor-next.microbit.org/sim-serial-expand-text/

[microbit-matt-hillsdon]

Change looks good.