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/CompletionOnImportedFunction/CompletionOnImportedFunction.dependency.kt

@@ -0,0 +1,9 @@
+package second
+
+class TestSecond {
+    fun testMethod() {
+
+    }
+}
+
+fun testFun() : TestSecond = TestSecond()

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

@@ -0,0 +1,9 @@
+package first
+
+import second.testFun
+
+fun test() {
+  testFun().<caret>
+}
+
+// EXIST: testMethod