Minor Docker Improvements

[ohsh6o]

User Story:

As an OSCAL developer, in order to make using the provided Docker container more usable with docker or docker-compose, I would like some improvements in dependency management, controlling their versions, and prestaging environment variables.

Goals:

This is a follow-up from some other issue discovered after #984. These are minor improvements, but seem worthwhile for NIST and community use.

• When running with Docker, the ARG build argument is not passed along to an environment variable with ENV, so we must continuously express things like docker run -e SAXON_VERSION=9.9.0-1 -v $(pwd):/oscal oscal -x -c "./oscal/build/ci-cd/copy-and-convert-content.sh -o ./oscal -a . -c ./src/config -w . --resolve-profiles" even though that is built into the container before runtime and can be added at build time to match the Dockerfile.
• The Dockerfile and docker-compose.yml file supply similar but different Saxon 9.x minor versions. This makes maintenance tedious and you have to Ctrl+F replace more files carefully if there is different behavior between docker and docker-compose when Saxon versions exhibit different behavior.
• Dockerfile was not specifying the same npm install behavior as Github Actions, leading to many repeat validation command errors for JSON content that are hard to sift through.

Dependencies:

None

Acceptance Criteria

• All OSCAL website and readme documentation affected by the changes in this issue have been updated. Changes to the OSCAL website can be made in the docs/content directory of your branch.
• A Pull Request (PR) is submitted that fully addresses the goals of this User Story. This issue is referenced in the PR.
• The CI-CD build process runs without any reported errors on the PR. This can be confirmed by reviewing that all checks have passed in the PR.