Provide more detailed error output

**Is your feature request related to a problem? Please describe.**

The current state of micropy-cli's error handling is weak. Errors such as #217 and #212 can and should have more detailed outputs when the occur, explaining why they happened and what to do about it.

**Describe the solution you'd like**

TODO

**Describe alternatives you've considered**

**Additional context**

Start by reading issues #217 and #212, then trace the current micropy-cli error-handling entry points that produce those failures. Define the expected explanation and remediation guidance for each error before implementing and testing the agreed output.

Written by the indexing model from the issue text.