EN auth: type cast before checking cookie expiration date
Add `ads` word to ignore list in `date_format` check

Fix #3423
EN checks: use an exception to skip check instead
EN checks: use any symbol except `}` instead of non-space symbol to define mustache placeholders.
EN checks: split mustache_placeholder_pairs check into two to properly deal with non-strict pairs

Fix #3422
EN checks: add more tests
Recover `fuzzy` state for obsolete units after resurrection

Fix #3421