Classify unknown HVT route types based on the corresponding value range

Such types are for example in use in the Norwegian Entur feed for air
and water transport, and were previously classified as "other".

src/loader/gtfs/route.cc

@@ -114,9 +114,21 @@ clasz to_clasz(int const route_type) {
     case 1506 /* Private Hire Service Vehicle */:
     case 1507 /* All Taxi Services */:
     case 1700 /* Miscellaneous Service */:
-    case 1702 /* Horse-drawn Carriage */:
-    default: return clasz::kOther;
+    case 1702 /* Horse-drawn Carriage */: return clasz::kOther;
   }
+
+  // types not in the above table but within category type ranges
+  if (route_type >= 1000 && route_type < 1100) {
+    return clasz::kShip;
+  }
+  if (route_type >= 1100 && route_type < 1200) {
+    return clasz::kAir;
+  }
+  if (route_type >= 1200 && route_type < 1300) {
+    return clasz::kShip;
+  }
+
+  return clasz::kOther;
 }
 
 color_t to_color(std::string_view const color_str) {

test/loader/gtfs/route_test.cc

@@ -39,7 +39,7 @@ TEST(gtfs, read_routes_berlin_data) {
       read_routes(tt, timezones, agencies,
                   berlin_files().get_file(kRoutesFile).data(), "CET");
 
-  EXPECT_EQ(8, routes.size());
+  EXPECT_EQ(9, routes.size());
 
   ASSERT_NE(end(routes), routes.find("1"));
   EXPECT_EQ("ANG---", tt.providers_[routes.at("1")->agency_].short_name_);
@@ -62,4 +62,7 @@ TEST(gtfs, read_routes_berlin_data) {
   EXPECT_EQ(clasz::kRegional, routes.at("812")->clasz_);
   EXPECT_EQ(color_t{0xFFB10093}, routes.at("812")->color_);
   EXPECT_EQ(color_t{0xFFFFFFFF}, routes.at("812")->text_color_);
+
+  ASSERT_NE(end(routes), routes.find("F11"));
+  EXPECT_EQ(clasz::kShip, routes.at("F11")->clasz_);
 }

test/loader/gtfs/test_data.cc

@@ -136,6 +136,7 @@ constexpr auto const berlin_routes_file_content =
 810,N04---,,"S+U Lichtenberg Bhf (Berlin) -- Senftenberg, Bahnhof",,100,http://www.vbb.de,,
 811,N04---,,"S+U Lichtenberg Bhf (Berlin) -- Altdöbern, Bahnhof",,100,http://www.vbb.de,,
 812,N04---,RB14,,,100,http://www.vbb.de,B10093,FFFFFF
+F11,F04---,,,,1203,,,
 )";
 
 constexpr auto const berlin_trips_file_content =