Fix pekko route naming

[samwright]

There are a few problems with the http.route values generated in pekko's instrumentation.

1. Path matching does not need to end with a PathEnd matcher, as the current solution assumes, e.g.:

pathPrefix("foo" ~ not("bar")) { complete("ok") }

will match /fooabc/123, but no http.route is generated. Given the glob-style approach of using * to represent a captured variable, I suggest the correct http.route here should be /foo**.

2. pathPrefix doesn't work as expected, e.g.

pathPrefix("a") {
  pathPrefix("b") {
    path("c") {
      complete("ok")
    }
  }
}

will match /a/b/c, but the http.route generated is abc.

This solves those issues, and adds a variety of PathMatchers to the tests.

[laurit]

will match /fooabc/123, but no http.route is generated. Given the glob-style approach of using * to represent a captured variable, I suggest the correct http.route here should be /foo**

I personally would prefer /foo* to /foo**

[samwright]

@laurit @masonedmison any other comments?