Validate `io.whalebrew.*` labels

[farkasmate]

Problem: If a typo is made in the label name whalebrew is silently ignoring it. For example io.whalebrew.config.volume would not add volumes to the image.

Goal: Help whalebrew image developers to catch these bugs

Example:

• Using whalebrew install or similar (validate/lint) in build pipelines would surface warnings or errors
• Check for these label names

Benefits:

• Better test coverage on whalebrew images

[tjamet]

Thanks for raising. Having a way to lint those labels is indeed a good idea. I am having a look at how to implement it.