Allow sorting by last branch commit

**Is your feature request related to a problem? Please describe.**
I have quite a few branches and can not always remember the name of them.

**Describe the solution you'd like**
It would be amazing if the branch list could be sorted my last-commit date.

**Describe alternatives you've considered**
Don't know of any.

该 issue 未指出任何文件、测试或入口点。首先定位分支列表及其现有的排序行为，然后检查如何获取分支最后一次提交的日期。完成标准是分支列表可以按最后一次提交的日期排序，并且该行为由适当的测试覆盖。

由索引模型根据 Issue 内容生成。