Foreign Key GA

Foreign Key feature has been supported for a long time. However, it's not GA yet. There are some existing issues about foreign key, and this issue will track the things which we'll need to do before mark it as GA.

# Known issues

* Consistency
- [x] https://github.com/pingcap/tidb/pull/55891
- [x] https://github.com/pingcap/tidb/pull/56349
- [x] https://github.com/pingcap/tidb/issues/56663
- [x] https://github.com/pingcap/tidb/pull/56661

* Compatibility
- [ ] https://github.com/pingcap/tidb/issues/43267 (WON'T FIX)
- [x] https://github.com/pingcap/tidb/issues/39712
- [x] https://github.com/pingcap/tidb/issues/28421 (Multi-schema change)
- [x] https://github.com/pingcap/tidb/issues/56458
- [x] https://github.com/pingcap/tidb/issues/56456
- [x] https://github.com/pingcap/tidb/issues/56681
- [x] https://github.com/pingcap/tidb/issues/56678
- [x] https://github.com/pingcap/tidb/issues/56701

* Add more tests
- [x] https://github.com/pingcap/tidb/issues/56365
- [x] https://github.com/pingcap/tidb/issues/56562
- [x] https://github.com/pingcap/tidb/issues/56563
- [x] https://github.com/pingcap/tiflow/pull/11703

* Others
- [x] https://github.com/pingcap/tidb/issues/49271

# Enhancement