intellij integration can be confusing

Use the reproducer Project provided here-> https://github.com/tg-freigmbh/protoexample

We have proto files in both subproject a and b, the tests (sourceset check) of b have a dependency to a, but the production code of a does not have a dependency to b.

So extracted-include-protos/check is marked as generated sources instead of a generated test-sources

Idealy we would like to turn off extracted-include protos für the checks sourceset, as protobuf compilation is only ever relevant for the main source set.
This causes even more confusion if the bundled protocol buffers plugin for intellij is enabled.

Intellij will now think that the protobuf files in a:main and b:main (actually it should be test) are different entities.

I will also create a ticket with jetbrains what they think how this should be resolved.