[New Feature] Create DAG to execute the Application Package generator

[LucaCinquini]

PM Ticket Reference: unity-sds/unity-app-build-trigger#2

Description:

Convert App Builds system into a docker container runnable in Airflow - Allows user to provide tokens, credentials. See Status of builds. Etc. Initial version should be what we're doing today. enhancements (future) should include pointing to an eCR repository, non-docker repo, etc. Needs Documentation. Should this be its own DAG that can run 'faster' than the cwl operators (e.g. SPOT instances).

Acceptance Criteria:

Docker Container Conversion: The App Builds system must be successfully converted into a Docker container.
Airflow Integration: Ensure the Docker container runs smoothly within the Airflow environment.
Validation and Testing: The Docker container and its integration with Airflow must be thoroughly validated and tested to ensure it operates without errors.
Documentation: Provide detailed documentation on the app-pack process, including steps taken, and configurations applied

Dependencies:
From U-ADS: Docker container to execute the Application Package Generation, together with complete documentation.