Check for deprecated method calls

[oliverklee]

Findings:

• DBAL things: fetch, fetchAll, fetchColumn, query, MysqliStatement
• ObjectManager::get in the StoragePageAgnostic trait and in one functional test: https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/10.4/Deprecation-90803-DeprecationOfObjectManagergetInExtbaseContext.html
• calls to deprecated oelib functions or Core functions that already are wrapped in a version switch
• MockBuilder->setMethods(): Add onlyMethods + addMethods and soft deprecate setMethods sebastianbergmann/phpunit#3687 -> use onlyMethods instead