ci(rh-shield-operator): enhance operator release pipeline

[aroberts87]

What this PR does / why we need it:

The old pipeline would simply build and push the operator and bundle images. This was a start, but left numerous manual steps to get the Operator itself certified. The changes in this PR add the following enhancements to the pipeline.

1. Generate the Bundle content in the pipeline a. Run the 'make bundle' command in the pipeline as opposed to requiring it be run beforehand. b. Since the pipeline guarantees the operator image itself will be built and pushed before the bundle is generated, we can set USE_IMAGE_DIGESTS=true when running 'make bundle' to include the image checksums in the bundle. This is a requirement for certification. c. The newly generated bundle content will be modified to include the annotations required for certification that are not created by the operator-sdk.
2. Trigger preflight certification

The act of certifying the operator will still require manual intervention.

Checklist

• Title of the PR starts with type and scope, (e.g. feat(agent,node-analyzer,sysdig-deploy):)
• Chart Version bumped for the respective charts
• Variables are documented in the README.md (or README.tpl in some charts)
• Check GithubAction checks (like lint) to avoid merge-check stoppers
• All test files are added in the tests folder of their respective chart and have a "_test" suffix