Specific error types for errors instead of &'static str

[ErisianArchitect]

Is your feature request related to a problem? Please describe.
Without specific error types, it can be difficult if not impossible to determine what the cause of the error is without reading the string, which makes debugging a little harder to do.

Describe the solution you'd like
These &'static str errors could be replaced with error types specific to those errors.

Describe possible drawbacks to your solution
This would not be a backwards compatible change.

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I don't mind attempting to contribute this to inkwell, but I don't want to change anything if someone thinks it's a bad idea.

[TheDan64]

Yes, I agree. This is mostly tech debt from the days before thiserror and rust having any sort of good error type guidlines

[ErisianArchitect]

I can make a rather opinionated attempt at making this change. I'm not sure what you would prefer in terms of errors, but I can give it a shot in my next pull request.

[ErisianArchitect]

#598

I've submitted a pull request.