Return code handling about rust-tss-esapi

[hug-dev]

Also I think we need to refactor the responsde code handling to make it less clunky:

let ret = Error::from_tss_rc(ret);
if ret.success() {
    ...
} else {
    ...
}

We should convert ret to a Result<(), Error>

[Superhepper]

I am not sure. I was just unable check if I got the error that I was interested in and I did some minor digging in the specifications but did not really come up with any answers.

From reading the specification we can say for a fact that we are not reporting the layer in software stack from where the error originated. That could be information that is worth providing.

[hug-dev]

As in we cover the TSS2_RC values but not the TSS2_ESYS_RC ones? Going through the spec there are also the TSS2_TCTI_RC values 😨

[Superhepper]

I have started to work on this and it is 'not to bad'. It seems as we are just missing a lot of information and in some cases when the error is originating from the software stack it self and in that case we might be doing something wrong. But the errors originating from the TPM are handled correct from what I can see.

But I will refactor the response code and add support for errors originating from the software stack. But this will probably require breaking the API.