Reusing same solution of org.springframework.web.socket.sockjs.transport.TransportType to avoid a loop and allocations of Enum.values().

Comment From: dfa1

@poutsma hello, just noticed that you did a nice commit to avoid some allocations in HttpStatus (7f1062159ee9926d5abed7cadc2b36b6b7fc242e). This doing same for HttpStatus.Series + some other minor fixes. What do you think?

Comment From: poutsma

I had the same idea of using a Map<Integer, HttpStatus>, but was convinced by @richardstartin that this was a bad idea because the common status codes fall outside the range of the Integer cache. See https://github.com/spring-projects/spring-framework/issues/26842#issuecomment-824717247.

So I am afraid I am going to have to decline this PR, as all the other changes seem to be cosmetic.