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/Object.kt

@@ -0,0 +1,10 @@
+trait I
+
+object O : I
+
+fun foo(): I = <caret>
+
+// EXIST: { lookupString: "O", itemText: "O", tailText: " (<root>)" }
+// EXIST: foo
+// EXIST: object
+// NUMBER: 3