Docker build/release pipeline; updated repo sync to use

General MR

Summary

1. Add the ability to build docker images via pipeline. Originally sourced from https://repo1.dso.mil/big-bang/team/tools/repo-sync/-/issues/62
2. Update repo sync to use said ability.

Open questions / feedback:

1. Does the way secrets are passed work? Specifically repo sync's use of gpg. The only alternative I could find is to store the artifacts in some secret manager like AWS secret manager or vault.
2. Are there better variable names to use for credentials that match up with what is already present?
3. Unsure of where to put the documentation update, because its entirely new functionality for the pipeline.
4. Do the AWS creds already exist for pipeline use? If so, are they the standard used by the AWS CLI (AWS_REGION, AWS_ACCESS_KEY, etc) or something else?