SeriesSaleImportForm: add tests

[0pdd]

The puzzle 1057-ae51bd20 from #1057 has to be resolved:

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

Line 6 in 6b40dca

// @todo #1057 SeriesSaleImportForm: add tests

The puzzle was created by Slava Semushin on 23-Jun-19.

[php-coder]

At least for the following cases:

• success
• form error
• field error

[php-coder]

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