[FEATURE REQUEST] Remove old versions of PowerShell modules.

### Please confirm these before moving forward.

- [x] I have searched for my feature proposal and have not found a work-in-progress/duplicate/resolved/discarded issue.
- [x] This proposal is a completely new feature. If you want to suggest an improvement or an enhancement, please use [this template](https://github.com/Devolutions/UniGetUI/issues/new?labels=enhancement&projects=&template=enhancement-improvement.yml&title=%5BENHANCEMENT%5D+%28Enter+your+description+here%29).

### Describe the new feature

I would love it if UniGetUI would remove all of those old versions PS modules on my systems. Maybe have a settings option to not do that for those who don't want it.

### Describe how this new feature could help users

It's currently a PITA to keep installed modules clean.