Provide suggestions if a function cannot be found

[baszalmstra]

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

https://github.com/mun-lang/mun/blob/cc839c3ce7727834b7b395ba8f0c2100d859b355/crates/mun_runtime/tests/functions.rs#L6-L28

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`

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  • You can fork this branch, which already contains a test to help you get started
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• [x] implement the feature and start a Pull Request with in the description: closes #412.

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[belagoesr]

I'll be taking this one!