Investigate Adblock pattern duplication
_Originally created by @sajolida on [#6909 (Redmine)](https://public-redmine-archive.tails.boum.org/code/issues/6909)_
Verify that all patterns from easylist (standard) are indeed in (at
least one of) the two other ones (easylist+fr and easylist+de).
Parent Task: tails/tails#6908
issue