feat(server): store and expose last updated date of gtfs data

shared/src/commonMain/kotlin/moe/lava/banksia/di/CommonModules.kt

@@ -7,6 +7,7 @@ val CommonModules = module {
     includes(PlatformModule)
 
     single { Database.build(get<PlatformDatabaseBuilder>().getBuilder()) }
+    single { get<Database>().versionMetadataDao }
     single { get<Database>().routeDao }
     single { get<Database>().shapeDao }
     single { get<Database>().stopDao }