jar tool should have an opt-out for validation when creating or updating a jar

The jar tool runs validation logic when creating and updating a jar (and when running the validation explicitly).

However, if a jar is built in multiple steps, while the final jar might be valid, one of the intermediate jars might not be. Since validation runs when using the create and update commands, as additional validation logic is added, some existing build setups might become invalid.

There's also the argument that running the validation logic multiple times while not really needed wastes time and resources. Only the final jar needs to be validated once, not every intermediate step.

The suggestion is to add a flag, such as '--skip-validation', that can be used when running the create or update commands, to allow such cases to continue working.