fix: quill describe panics on ad_hoc unsigned binary

[spiffcs]

Fix: update quill details to not panic on ad_hoc unsigned binary

Reproduction Steps on OSX:

make build
./snapshot/darwin-build_darwin_amd64_v1/quill describe -vv ./snapshot/darwin-build_darwin_amd64_v1/quill 

Panic: on main:

No Panic with fix:

Details:

getSignatures features a couple of error branches where a panic is possible.

This PR refactors getSignatures into a few smaller functions and removes those panics

• move BlobDetails out of the signature code and into its own function
• warn if content info or signed data cannot be parsed
• build signers, certs, verifiedCerts, and signature timestamps separately
• return SignatureDetails early and append BlobDetails

Signed-off-by: Christopher Phillips [email protected]

[wagoodman]

really solid clean up 🙌

[spiffcs]

@wagoodman reduced the output to debug so now -vv is needed to see the debug output which were previously Warnf

A new error message has been included in the report in stdout showing there is no cryptographic signature