[WIP PATCH RFC] Add class and methods to expand `access` tags

[taylor.smock]

This patch doesn't expand conditional tags. It replaces values in ConditionalKeys.java (specifically the RESTRICTION_VALUES and TRANSPORT_MODES).

This is so that other classes can expand access values (so hgv=yes expands to hgv=yes + hgv_articulated=yes).

Future use cases:

• mapcss:

  way[highway][motorway][!foot][access("foot") == "yes"] {
      throwOther: "Probable bad access tag";
  }
  

• Routing tests

  public boolean usable(Way way, String transportMode) {
      List<String> possibleModes = Access.getTransportModes().stream().filter(way::hasKey).collect(Collectors.toList());
      Map<String, String> accessMap = new HashMap<>();
      possibleModes.forEach(mode -> Access.mergeMaps(accessMap, Access.expandAccessMode(mode, way.get(mode))));
      return Access.getPositiveAccessValues().contains(accessMap.getOrDefault(transportMode, "no"));
  

[taylor.smock]

Create class for access tags