Follow-up to the T349757: [RFC] Community configuration 2.0: Validating site configuration discussion.

In T349757#9308800, @Daimona wrote:

In T349757#9308036, @daniel wrote:

Experience has also shown that is its beneficial to maintain the schema as constants in a PHP class, from which we can then generate a JSON Schema. This is nice because we can use constants for things like namespace IDs, and can make use of (e.g. nullable types like "?string", or use "list" and "map" rather than "array" and "object").

While I'm unsure about the implementation details, I strongly agree with the idea of using PHP things like constants and types. This is one of the main disadvantages of extension.json files.

Let's consider this approach its implementation in Community configuration.