Refactor Docker compose configuration to run multiple portals at same time

[pollardld]

Fixes to improve running multiple portals at once.

Docker Compose and Volume Configuration Updates:

• Switched the order of Docker Compose files in the COMPOSE variable in Taskfile.yml so that docker/compose.yml is loaded before the core base file, ensuring the correct override order.
• Updated the app service in docker/compose.yml to use the correct build context (../../) and Dockerfile path (madrona-apps/wcoa/docker/Dockerfile) for clarity and maintainability.
• Refactored all app-related volume mounts in docker/compose.yml from short-form to long-form type: bind syntax with create_host_path: false, which is more explicit and compatible with newer Docker Compose versions.

Dependency Management:

• Added a new docker/requirements.txt file as a placeholder for project-specific Python dependencies required by the Docker image.