chore: enhance dapryml schema validation

[IvanJobs]

This PR comes to a stage when we can discuss specific topics.

[philliphoff]

While this is a good start, there's potentially a higher-level set of validation that could be useful to developers. For example, where a property requires a path, ensure that that path exists or, when the developer is adding the port, provide a default that matches the application settings. That's more semantic analysis rather than the syntactic done through this JSON schema and is done through language servers and related APIs.