Cleanup of relative redirect handling #11014

+ Handle request relative redirects
+ Moved to Response
+ Changed default to allow relative

jetty-ee9/jetty-ee9-nested/src/test/java/org/eclipse/jetty/ee9/nested/RequestTest.java

@@ -1329,7 +1329,7 @@ public void handle(String target, Request baseRequest, HttpServletRequest reques
             "Connection: close\n" +
             "\n");
         assertThat(response, containsString(" 302 Found"));
-        assertThat(response, containsString("Location: http://myhost/foo"));
+        assertThat(response, containsString("Location: /foo"));
     }
 
     @Test