Feature request: derive PartialEq for enum Error

[whitevegagabriel]

As part of my implementation, I define a custom Error, one variant which wraps an Error enum that is generated by PDL.

In some of my tests, I check that I get the expected error types, which is simplified if I derive PartialEq for my Error enum.

Problem is, I have to implement PartialEq for the PDL-generated Error enum if I want one of my error variants to wrap it.

Is it feasible to derive PartialEq for Error enums?

[whitevegagabriel]

Another note:
I am happy to create a PR to implement this!