Ignore-files are important for shaping the build context, especially when the build context contains a large amount of files/data.

While docker-java v3.4.0 already supports .dockerignore at the root of the build context, it would be beneficial to additionally support Dockerfile-specific ignore-files.

• Feature parity with docker build. See the documentation for details on how this works.
• Allow use cases where multiple Dockerfiles live in the same directory, while having the ability to distinctly filter the build context.
• Allow use cases where multiple Dockerfiles live in different directories and reference the same build context, while having the ability to distinctly filter the build context.