Kotlin.git test infrastructure: Inspection for unresolved directives

It would be nice to have comprehensive handling of unknown/unchecked test directives in Kotlin (see parent issue [KT-83960](https://youtrack.jetbrains.com/issue/KT-83960/Check-tests-for-unused-unknown-directives) for details).

As a first approximation/interim solution, we could implement an inspection in the compiler dev kit plugin for completely unresolved directives. This would help with a subset of use-cases, where the directive does not exist anywhere at all (e.g. typos).

It wouldn't be a complete solution, because some directives could be resolved, but still not handled by any of the runners of the current test, which would be missed by this inspection; nonetheless, it is a good first step to solving [KT-83960](https://youtrack.jetbrains.com/issue/KT-83960/Check-tests-for-unused-unknown-directives), and could be implemented immediately, while that issue is blocked.