[AA] Add KotlinModuleDependentsProvider.getRefinementDependents

- When calculating sealed inheritors for expect classes, we need to
  expand the search scope to modules with a depends-on/refinement
  dependency on the module containing the expect class, as these modules
  may contain additional sealed inheritors. `getRefinementDependents`
  allows us to get these refinement dependents to build the proper
  search scope.

^KT-66013

analysis/project-structure/src/org/jetbrains/kotlin/analysis/project/structure/KotlinModuleDependentsProvider.kt

@@ -32,6 +32,12 @@ public abstract class KotlinModuleDependentsProvider {
      */
     public abstract fun getTransitiveDependents(module: KtModule): Set<KtModule>
 
+    /**
+     * Returns all refinement/depends-on dependents of [module], excluding [module] itself. The result is transitive because refinement
+     * dependencies are implicitly transitive.
+     */
+    public abstract fun getRefinementDependents(module: KtModule): Set<KtModule>
+
     public companion object {
         public fun getInstance(project: Project): KotlinModuleDependentsProvider =
             project.getService(KotlinModuleDependentsProvider::class.java)