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/NotImportedExtensionForImplicitReceiver/NotImportedExtensionForImplicitReceiver.dependency.kt

@@ -0,0 +1,13 @@
+package second
+
+import first.C
+
+fun String.helloFun() { }
+
+fun String.helloWithParams(i : Int): String = ""
+
+val String.helloProp: Int get() = 1
+
+val C.helloForC: Int get() = 1
+
+fun Int.helloFake() { }

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

@@ -0,0 +1,14 @@
+package first
+
+class C {
+    fun String.firstFun() {
+        hello<caret>
+    }
+}
+
+// EXIST: helloFun
+// EXIST: helloWithParams
+// EXIST: helloProp
+// EXIST: helloForC
+// ABSENT: helloFake
+// NUMBER: 4