Support for RFC 8141

[carlos-verdes]

Description I would like to have a parser for RFC 8141 URNs.

Example We can see an example implementation on the next library: https://github.com/slub/urnlib

  URN urn2 = URN.rfc8141().parse("urn:examle:foo/1234?=cq=cz#bar");

  // Access fragment part of a supposedly RFC 8141 compliant URN
  if (urn2.supports(RFC_8141)) {
    String fragment = ((URN_8141) urn2).getRQFComponents().fragment();
  }