[FEATURE REQUEST] Provide uninstall options within Discover Packages tab

### 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/marticliment/WingetUI/issues/new?assignees=marticliment&labels=enhancement&projects=&template=enhancement-improvement.yml&title=%5BENHANCEMENT%5D+%28Enter+your+description+here%29).

### Describe the new feature

_I believe it's intended behavior for you not to list uninstall options on a package listed under the Discover Packages tab, so I am submitting this as a feature request rather than bug. After all, Uniget does recognize the package is installed via the checkmark indicator_

The feature I would like to have added to Uniget is to provide uninstall operations onto a package listing when viewing the Discover Packages tab if a package is already installed.

### Describe how this new feature could help users

1. QoL
- Consider the case where a user wants to uninstall their current package for a different version (eg. stable to nightly). With this feature, they could do so more easily without having to switch back and forth
2. Despite it seemingly being intended not to have the uninstall options currently, I think it's more appropriate to have the uninstall options since the package is installed already after all. **In fact, when you right click -> *Package details, it still only shows install options rather than uninstall too*