Support for template routes with encoded separator in RSocketRequester

[rwinch]

Affects: 5.2.0.BUILD-SNAPSHOT

RSocketRequester allows a route to be provided. It would be nice if there were a simple way to perform encoding of the route. For example, if a route were foo.{id} and id contains a . then it would not work. It would be nice if there were a simple mechanism to encode the route.

[rstoyanchev]

I've made two updates:

1. For the responder side PathPattern now supports HTTP ("/" separator with decoding of path segment values and parsing of path params) vs Message Route style parsing ("." separator with no decoding and no parsing of path params). The latter does decode encoded sequences for the separator char and is enabled with the default constructor of PathPatternRouteMatcher.
2. For the requester side, RSocketRequester now supports route variables to be expanded into the route, also replacing any "." with "%2E".