Series import: add support for alternative price

It should be possible to extract alternative price/currency.

Example:
```
m.w.f.s.i.SeriesInfoExtractorServiceImpl : Determine price from 'Новая цена 64.00 руб ($1.08 / €0.98)'
m.w.f.s.i.SeriesInfoExtractorServiceImpl : Price is 64.00
```
In this case, we can extract alternative price in USD (or EUR).

It should be added into 2 places: series import and series sale import.