Dependency evaluation for json schema validation

Problem/Motivation

JSON:API uses justinrainbow/json-schema to validate that the responses conform to the {JSON:API} specification. For this to happen:

• You need core-dev installed.
• You need assertions enabled (typically via local.settings.php).

The Single Directory Components module, being proposed in #3340712: Add Single Directory Components as a new experimental module, makes further use of this dependencies in the same scenario. In this case it validates the data a component receives, against the schema the component author has written.

Proposed resolution

We want to evaluate adding justinrainbow/json-schema as a dependency of drupal/core. This way we'll be able to do the validation by only enabling assertions.

Additional references:

1. https://git.drupalcode.org/project/drupal/-/merge_requests/3432#note_160873
2. https://git.drupalcode.org/project/drupal/-/merge_requests/3432#note_157176