suggest correctly shaped functional types if extracting functional expression without context: initial (IDEA-125510)

java/java-tests/testData/refactoring/introduceVariable/MethodRefNotInContext.after.java

@@ -0,0 +1,7 @@
+import java.util.function.IntConsumer;
+
+class Foo {
+    void test() {
+        IntConsumer l = System::exit;
+    }
+}