VSA JSON struct tags

[ramonpetgrave64]

The json truck tags for VSA v1 seem like they should be in camel case, instead of snake case.

This means that for the VSA predicate in a document formatted like the slsa.dev example the only parsed fields unmarshalled successfully would be policy, and partially for verifier, which seems to be missing verifier.version.

In slsa-framework/slsa-verifier, I have defined the json struct tags that I think should be correct.

• https://github.com/ramonpetgrave64/slsa-verifier/blob/489e79138b5050e7d719a1c57610b684ee63d53f/verifiers/internal/vsa/v1.0/vsa.go#L25-L42