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/smart/inheritors/1.kt

@@ -0,0 +1,8 @@
+import java.io.InputStream
+
+fun foo(): InputStream {
+    return <caret>
+}
+
+// EXIST: ByteArrayInputStream
+// EXIST: FileInputStream

idea/idea-completion/testData/smart/inheritors/2.kt

@@ -0,0 +1,5 @@
+fun foo(): List<String> {
+    return <caret>
+}
+
+// EXIST: { lookupString: "ArrayList", itemText: "ArrayList<String>", tailText: "(...) (java.util)" }

idea/idea-completion/testData/smart/inheritors/3.kt

@@ -0,0 +1,31 @@
+trait T
+
+open class A : T
+
+class B : A()
+
+fun foo(): T {
+    open class Local1 : T
+
+    class Local2 : Local1()
+
+    return <caret>
+}
+
+fun x() {
+    /*TODO*/
+    /*class Local3 : T*/
+}
+
+open class C : T
+
+class D : C()
+
+
+// EXIST: A
+// EXIST: B
+// EXIST: Local1
+// EXIST: Local2
+// ABSENT: Local3
+// EXIST: C
+// EXIST: D