Fix #69: Do not unwrap when extracting data from responses

[msirringhaus]

There still are a bunch of other unwraps in the code (some of which you can even see in this patch), mostly parsing either CBOR or other binary stuff in the crypto-section.

Not sure, if we want to address them here as well, and if so, how.
For CBOR-related things, we could basically also just return the serde errors?

[AlfioEmanueleFresta]

For CBOR-related things, we could basically also just return the serde errors?

I'm not sure the serde errors will be useful to the caller. IMO, the smaller/simpler the error enum, the more likely it is to be handled correctly by clients.

We could log these errors and return InvalidDeviceResponse?

[msirringhaus]

Added a similar macro for CBOR parsing now.
There are still a bunch of other unwraps in the code, but I think those should be addressed by another PR. They seem less likely to be triggered any time soon.