Optimize a search within user's collection

[0pdd]

The puzzle 1098-de488059 from #1098 has to be resolved:

mystamps/src/main/java/ru/mystamps/web/feature/series/SeriesController.java

Line 511 in 742b7d8

// @todo #1098 Optimize a search within user's collection

The puzzle was created by Slava Semushin on 24-Jul-19.

[php-coder]

What we can improve here:

• N+1 queries could be easily reduced to 2 if CollectionService.isSeriesInCollection() will be modified to take varargs instead of a single series
• (ideally) we should search in user's collections only (at this moment we first search on site database and later removes everything that user doesn't have in its collection)
• it's own service method should/could be introduced

[php-coder]

After #1123 we don't use CollectionService.isSeriesInCollection() on collection info page, so now it's being used only for search in a collection.