- use SavingEntityRepository from T230335: Create SavingEntityRepository
- after successful saving
- update baseRevisionId in entity state
- update entity in entity state
- fix tests
- [fix ForeignApi type](https://gerrit.wikimedia.org/r/533946)
- [add wgUserName](https://gerrit.wikimedia.org/r/533947)
- [load ForeignApi](https://gerrit.wikimedia.org/r/533948)
- add statements getter
- [inject WritingEntityRepository](https://gerrit.wikimedia.org/r/533950)
- fix types
- add save action
- rename