UnigetUI portable still creates a directory outside the app directory and registry entries as well

### 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 improvement refers to an existing feature. If you want to suggest a new feature, please use [this template](https://github.com/Devolutions/UniGetUI/issues/new?labels=new-feature&projects=&template=feature-request.yml&title=%5BFEATURE+REQUEST%5D+%28Enter+your+description+here%29).
- [x] This improvement is not a bug. If you want to report a bug, please use [this template](https://github.com/Devolutions/UniGetUI/issues/new?labels=bug&projects=&template=bug-issue.yml&title=%5BBUG%5D+%28Enter+your+description+here%29).

### Describe the improvement

First, thanks for a good software app updater, based on well known package installers.

Also, thanks for making a 'portable' version, not needing an install.

However, the 'portable' version creates folder and registry entries.

If they can be avoided, will make this app fully portable with zero footprint outside its app directory.

* Folders created at C:\Users\ *** \AppData\Local\UniGetUI\
(whatever data needs to be stored here by UniGetUI, can be stored in the app directory itself?)

* Multiple registry entries (which may not be UniGetUi's doing directly, but Windows keeping track of which app is run).

Thanks for considering.

### Describe how this improvement could help users

Can make this app fully portable, with zero footprint outside its app directory.