Initial support for KT-7090 Completion for callable references

#KT-7090 Fixed

idea/idea-completion/testData/handlers/basic/callableReference/NonEmptyQualifier.kt

@@ -0,0 +1,11 @@
+class C {
+    fun foo() {
+        val v = D::<caret>
+    }
+}
+
+class D {
+    fun memberFun(s: String){}
+}
+
+// ELEMENT: memberFun