**Motivation**
Right now, not all of our config variables around show changes in moved paragraphs are handled the same way. Their behavior should be unified, though
**Task**
Unify the treatment of the config variables we introduced to all be set via `ini_set` (see the config section in https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/php/wikidiff2/+/refs/heads/master/README). The only current outlier is `$wgWikiDiff2MovedParagraphDetectionCutoff`.
[x] Prepare core to use the new method signature
[x] ~~Update operations/mediawiki-config to use ini_set **in addition** to the PHP variable.~~
[x] Update the wikidiff2 code to get rid of the PHP variable.
[] Release and deploy wikidiff2 version 1.8.0 with change signature.
[] Remove the not needed PHP variable from operations/mediawiki-config.
[] Remove the not needed PHP code from core. Remember to add it to the release notes to make backwards compatibility clear