Summary:
## Changes in this pull request
Issue fixed: https://github.com/Instagram/IGListKit/issues/1275
This PR is straintforward solution as mentioned in https://github.com/Instagram/IGListKit/issues/1275. When I finished it, I realized that it is not a problem in `IGListCollectionViewLayout Partial Optimization` and `IGListBindingSectionController` deserved it. Maybe `IGListCollectionViewLayout` is rarely used because of great builtin UICollectionViewFlowLayout or cells in section rarely need changing their sizes in practices.
Despite it is not `IGListCollectionViewLayout`'s fault, I think it can be more optimized against `invalidateLayoutWithContext`. I would like to make an another PR to optimize it.
Due to this PR just giving a proposed solution, it lacks of adding tests and changing log. When this solution is accepted, I would like to complete these todos.
### Checklist
- [x] All tests pass. Demo project builds and runs.
- [x] I added tests, an experiment, or detailed why my change isn't tested.
- [x] I added an entry to the `CHANGELOG.md` for any breaking changes, enhancements, or bug fixes.
- [x] I have reviewed the [contributing guide](https://github.com/Instagram/IGListKit/blob/master/.github/CONTRIBUTING.md)
Pull Request resolved: https://github.com/Instagram/IGListKit/pull/1285
Reviewed By: candance
Differential Revision: D15592807
Pulled By: lorixx
fbshipit-source-id: ae06abce896341509de4f3dfb73b3a7bc0a68c51
