When we updated the upstream wikimedia eslint config in T209932, we deactivated a lot of rules primarily concerning suboptimal jQuery usage, because that was beyond the scope of that ticket. Nonetheless, these rules are reasonable (#106 on GitHub) and should be implemented. Also the max-statements-per-line rule should be enabled and the code adjusted.
Acceptance Criteria
- enable rules and fix code in Wikibase (~119 linting errors) - rules disabled
- enable rules and fix code in WikibaseLexeme (~9 linting errors) - rules disabled
- enable rules and fix code in WikibaseQualityConstrains (~0 linting errors)