If a mun function cannot be found when trying to execute some Mun code via the runtime, include suggestions of correct function names.

Current Behaviour

Desired behavour
The returned error message contains an additional line recommending the function name/path that's the closest match, something like:

help: there is a function with a similar name: `main`

Good first issue process:

• read our contributing guidelines
  • You can fork this branch, which already contains a test to help you get started
• claim this issue (assign yourself or comment below)
• implement the feature and start a Pull Request with in the description: closes Provide suggestions if a function cannot be found #412.

If this is your first PR, welcome 🎉 😄