Cosign Class Unit Tests

Merge Request Description

Merge Request BOE

Risk

Modified Cosign class for post-init variable usage

Rollback Plan

Revert MR

Testing

Update to Cosign class vars tested in Mario: https://code-ib-mario.staging.dso.mil/dsop/redhat/ubi/ubi8/-/pipelines/2933

Closes #695 (closed)