[FEATURE REQUEST] Thumbnail view of the package to be installed

### 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

UniGetUi does not currently have a feature to display thumbnails of the packages to be installed; this is important because an image can give a more general idea of ​​the software to be installed.

### Describe how this new feature could help users

When selecting a package, right-clicking and choosing "Package Details" from the UniGetUI pop-up menu displays a window with package details, including one or more software thumbnails.

I propose keeping this functionality, but also opening a banner below the packages with general details of the software to be installed, including one or more thumbnails, when a package is selected. If no package is selected, this banner should be hidden.

I've attached a couple of screenshots: the first shows the current view of UniGetUI, and the second shows how this feature could be implemented.

Beginne mit der Auswahl eines Pakets und öffne die vorhandene Ansicht "Package Details", um zu verstehen, wie Paketdetails und Miniaturansichten derzeit dargestellt werden. Verfolge dann die UI für die Paketauswahl und ermittle, wie ein Banner unterhalb der Paketliste dieselben Details anzeigen und ausgeblendet werden könnte, wenn nichts ausgewählt ist; fertig ist die Aufgabe, wenn das Banner die angeforderten Softwaredetails und Miniaturansichten nur für das ausgewählte Paket anzeigt.

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