ImageFromDockerfile does not support authenticated pulls

ImageFromDockerfile doesn't work if base layer(s) need to be pulled from an authenticated registry and if those images are not already pulled.

For example:

# Dockerfile
FROM my.authenticated.registry/somerepo/someimage

will result in a failure at image build time, even if the user has working credentials available on their machine (for example, a CLI docker pull or docker build works).

It looks like BuildImageCmd's withBuildAuthConfigs(AuthConfigurations); gives us an opportunity to improve this - however we'd have to perform a lookup for credentials for each image first.

I think it should be feasible to:

• do a minimal parse of the Dockerfile to extract any FROM x [--as=y] declarations
• run each image name found through RegistryAuthLocator and obtain an auth configuration for each registry
• provide the auth configurations to BuildImageCmd

The main difficulty would be that we have a few different ways in which the Dockerfile flows through Testcontainers, so we'd need to make sure we capture Dockerfile content at the right time.