Import series: add support for Yvert catalog numbers

[0pdd]

The puzzle 694-424e441b from #694 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/controller/dto/ImportSeriesForm.java

Line 90 in 712c623

// @todo #694 Import series: add support for Yvert catalog numbers

The puzzle was created by Slava Semushin on 08-Jul-18.