Integration: Fix verifier codec

[jmcardon]

#210 unintentionally broke a codec chainweb depends on. This PR fixes the signer codec + adds roundtrip tests + a regression for ensuring pact-5 can deserialize prod values.

PR checklist:

• Test coverage for the proposed changes
• PR description contains example output from repl interaction or a snippet from unit test output
• (If Relevant) Documentation has been (manually) updated at https://docs.kadena.io/pact

Additionally, please justify why you should or should not do the following:

• Benchmark regressions
• Confirm replay/back compat (Ignore until core release)
• (For Kadena engineers) Run integration-tests against a Chainweb built with this version of Pact (Ignore until core release)

[jmcardon]

Note: This PR is blocked on making CI pass. We need to ensure that we have the regression sqlite file cached in the runners somehow