Add message to thrown Fido2VerificationException

[abergs]

To help debugging/reporting

[aseigler]

We should probably come up with a standard exception message format for the whole project and adhere to that.

[abergs]

Yes. I think that message standard should include the expected and supplied value, similiar to unit testing exceptions: "Type was invalid. Expected 'create' but was 'something else'

[aseigler]

All thrown exceptions currently have messages now, but have different formats.

[abergs]

Let's rewrite them where possible per my suggestion above. Pattern:
"{COMPLAINT/MESSAGE}. Expected 'X' but was 'Y'

The expected but was should only be added "where it makes sense".

For null values we might as well throw:
"'A' was null. Expected string but was null".

I can write a new constructor which formats it this way.

[iamcarbon]

@abergs I think we made good progress on the error messages over the last 4 years. The messages are pretty good now! Can we close this issue?

[abergs]

We have indeed @iamcarbon