Created module idea-test-framework and moved classes needed for idea tests there

Moved tests for completion and their test data into module idea-completion

idea/idea-completion/testData/smartMultiFile/Inheritors/KotlinInheritors.kt

@@ -0,0 +1,17 @@
+package p2
+
+trait KotlinTrait
+
+open class KotlinInheritor1 : KotlinTrait
+
+class KotlinInheritor2(s: String) : KotlinInheritor1()
+
+abstract class KotlinInheritor3 : KotlinTrait
+
+class C {
+    private class PrivateInheritor : KotlinTrait
+}
+
+object ObjectInheritor : KotlinTrait
+
+// ALLOW_AST_ACCESS