Implement rendering of raw types

Also add some clarification in spec

idea/testData/codeInsight/overrideImplement/implementJavaRawSubclass/foo/B.java

@@ -0,0 +1,6 @@
+package foo;
+import java.util.*;
+
+public interface B<T> {
+    B<String> foo(List<String> x, String y);
+}