Create Docker base images with only the required tools

[mnonnenmacher]

For tools that use ORT as a library it would be very useful to publish Docker base images that contain only the required tools, but not ORT itself. This would make it easier to build custom Docker images based on the same tool installation routines that have been verified by the ORT functional tests.

For the ORT Server project, it would be great if ORT would publish separate analyzer and scanner images that could be used as base images for the project's own Docker images.