Add alias support for base images check

[tomaszbarwicki]

Creating an issue for that for future fix.

At the moment quality check tool doesn't support 'aliases' in the Dockerfile i.e 'FROM base AS final' hence the check is reporting it as not allowed image.

Testing Quality Guideline: TRG 4.02 - Base images
Start finding Dockerfiles at ./
Found Dockerfiles: docker/Dockerfile-administration-service,
docker/Dockerfile-iam-seeding,
docker/Dockerfile-maintenance-service,
docker/Dockerfile-marketplace-app-service,
docker/Dockerfile-notification-service,
docker/Dockerfile-portal-migrations,
docker/Dockerfile-processes-worker,
docker/Dockerfile-provisioning-migrations,
docker/Dockerfile-registration-service,
docker/Dockerfile-services-service
Failed! Guideline description: We are aligning all product Docker images to a set of approved ones. This also makes it easier to properly annotate the used images as dependency
We want to align on docker base images. We detected a Dockerfile specifying base AS final, base AS final, base AS final, base AS final, base AS final, base AS final, base AS final, base AS final, base AS final, base AS final
Allowed images are:
- eclipse-temurin
- nginxinc/nginx-unprivileged
- mcr.microsoft.com/dotnet/runtime
- mcr.microsoft.com/dotnet/aspnet
More infos: https://eclipse-tractusx.github.io/docs/release/trg-4/trg-4-02

Example Dockerfiles: https://github.com/eclipse-tractusx/portal-backend/tree/main/docker