SeriesSalesList: add tests

[0pdd]

The puzzle 1329-5cbf2e5d from #1329 has to be resolved:

mystamps/src/main/frontend/src/components/SeriesSalesList.js

Line 6 in 7599f6b

// @todo #1329 SeriesSalesList: add tests

The puzzle was created by Slava Semushin on 05-Jan-21.

[php-coder]

This issue depends on #1484 where Jest and all required test dependencies will be added.