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/basic/multifile/NoExtForOuterFromNested/NoExtForOuterFromNested.dependency.kt

@@ -0,0 +1,6 @@
+package second
+
+import first.OuterClass
+
+fun OuterClass.outerExtension() {
+}

idea/idea-completion/testData/basic/multifile/NoExtForOuterFromNested/NoExtForOuterFromNested.kt

@@ -0,0 +1,12 @@
+package first
+
+class OuterClass {
+    class Nested {
+        fun foo() {
+            out<caret>
+        }
+    }
+}
+
+// INVOCATION_COUNT: 2
+// ABSENT: outerExtension