sort by duration

### Checklist - [x] I have used the search function for [**OPEN**](https://github.com/XilinJia/podcini/issues) issues to see if someone else has already submitted the same feature request. - [x] I have **also** used the search function for [**CLOSED**](https://github.com/XilinJia/Podcini/issues?q=is%3Aissue+is%3Aclosed) issues to see if the feature was already implemented and is just waiting to be released, or if the feature was rejected. - [x] I will describe the problem with as much detail as possible. - [x] This request contains only one single feature, **not** a list of multiple (related) features. ### App version 7.3.5 (3020342) ### Where did you get the app from Fdroid ### Problem you may be having, or feature you want If possible please add a option for sorting podcast by duration ### Suggested solution _No response_ ### Screenshots / Drawings / Technical details _No response_