Support package-level non-public marker

Instead of specifying a list of packages, it should be possible to specify a marker, for example [`@ApiStatus.Internal`](https://github.com/JetBrains/java-annotations/blob/b41de54f50e463211c71435c0fd86edeb9e3a152/common/src/main/java/org/jetbrains/annotations/ApiStatus.java#L73C25-L73C25)