Support Gradle Problems API for errors and warnings

Recent Gradle provides [Problems API](https://docs.gradle.org/current/samples/sample_problems_api_usage.html) to tell details of errors or warnings, and easy to interact with IDE ( https://youtrack.jetbrains.com/issue/IDEA-352280 ) or CI systems ( https://github.com/gradle/actions/issues/30 ).

And since Kotlin 2.2, [compiler and gradle plugin support it](https://kotlinlang.org/docs/whatsnew22.html#integration-of-problems-api-within-kgp-diagnostics).

I'm guessing KSP (gradle plugin) is also assuming that it will have to provide equivalent functionality.

Start by reading the linked Gradle Problems API sample and Kotlin 2.2 diagnostics integration notes, then inspect the KSP Gradle plugin area mentioned in the issue. Define how KSP errors and warnings should be exposed through the API and verify that IDE or CI consumers receive the expected problem details.

Written by the indexing model from the issue text.