Zoning: Add mode to show station catchment only where station window open.

src/zoning_gui.cpp

@@ -38,6 +38,7 @@ static const StringID _zone_type_strings[] = {
 	STR_ZONING_AUTHORITY,
 	STR_ZONING_CAN_BUILD,
 	STR_ZONING_STA_CATCH,
+	STR_ZONING_STA_CATCH_OPEN,
 	STR_ZONING_BUL_UNSER,
 	STR_ZONING_IND_UNSER,
 	INVALID_STRING_ID
@@ -48,6 +49,7 @@ static const ZoningEvaluationMode _zone_type_modes[] = {
 	ZEM_AUTHORITY,
 	ZEM_CAN_BUILD,
 	ZEM_STA_CATCH,
+	ZEM_STA_CATCH_WIN,
 	ZEM_BUL_UNSER,
 	ZEM_IND_UNSER,
 };