[Patch] Check runways,aerodromes for missing tags in validator

[maxerickson@…]

They aren't well adapted for global use but the simple rules I use locally flag many easy improvements:

*[aeroway=aerodrome][!faa]{
  group: tr("Airport Tagging");
  throwWarning: tr("Airport without faa code.");
}

*[aeroway=helipad][!faa]{
  group: tr("Airport Tagging");
  throwWarning: tr("Helipad without faa code.");
}

*[aeroway=aerodrome][!icao][faa!~/\d/],
*[aeroway=aerodrome][!iata][faa!~/\d/]{
  group: tr("Airport Tagging");
  throwWarning: tr("Airport without {0} code.", "{1.key}");
}

*[aeroway=runway][!ref],
*[aeroway=runway][!surface]{
  group: tr("Airport Tagging");
  throwWarning: tr("Runway missing {0}.", "{1.key}");
}

The [faa!~/\d/] selector suppresses the warnings for small US airports, where the FAA usually assigns an identifier that contains a number.