Error enum for CAN errors

[therealprof]

We need an enum of error kinds suitable for CAN (Controller Area Network) errors.

Checklist for the implementation:

• [ ] Public enumeration for an embedded peripheral with a recognisable name, marked as #[non_exhaustive]
• [ ] Useful doc string for the enumeration
• [ ] Generic and recognisable enumeration variants universally applicable to the peripheral
• [ ] Docstring per variant with a relatable explanation of the purpose (can contain a specific example if useful for illustration)
• [ ] Contains an Impl(ImplError) variant

cf.

https://github.com/therealprof/embedded-error/blob/6b4cc085d70b3af8ccadeef0dbf444593e6af902/src/lib.rs#L15-L32