How to translate facet filter view search assertions/statements into Russian?
I think you can just import your own translations, creating a simple *.po file.
The structure of that file you can get from https://www.gnu.org/savannah-checkouts/gnu/gettext/manual/html_node/PO-Files.html (or just google the example).
Import your own translations available by uri [yoursite]/admin/config/regional/translate/import