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/injava/NestedClassMembers2.java

@@ -0,0 +1,8 @@
+public class Testing {
+    public static void test(mockLib.foo.LibClass p) {
+        p.getNested().<caret>
+    }
+}
+
+// EXIST: getValInNested
+// EXIST: funInNested