Move the following classes to namespace:
- [ ] PageTranslationHooks (Might be difficult) - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/823618
- [x] TPException - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/817697
- [x] TranslatableBundleDeleteJob - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/815315
- [x] TranslatableBundleLogFormatter - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/816354
- [x] TranslatableBundleMoveJob - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/815297
- [ ] TranslatablePage - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/817770
- [ ] TranslateRenderJob - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/820099
- [ ] TranslationsUpdateJob - https://gerrit.wikimedia.org/r/c/mediawiki/extensions/Translate/+/820114
In addition to moving the classes to namespace:
* Add dependency injection
* Remove usage of deprecated methods
* Use strict types
* Check for external users of the class / methods