Fixed import of JS source sets with Both mode

Added flag indicating that source set naming contract is violated. In this case disambiguition classifier is ignored in IDE.
#KT-37562 Fixed

libraries/tools/kotlin-gradle-plugin-api/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTarget.kt

@@ -28,6 +28,7 @@ interface KotlinTargetComponent : SoftwareComponent {
 interface KotlinTarget : Named, HasAttributes {
     val targetName: String
     val disambiguationClassifier: String? get() = targetName
+    val useDisambiguitionClassifierAsSourcesetNamePreffix: Boolean
 
     val platformType: KotlinPlatformType