Utilize screenspace more efficiently

[fluflic]

It feels like the space of the add-on could be used more efficiently. Maybe there is a way to restructre the layout so that more items can be shown at once. E.g. by moving the filter and sort settings to a sidebar and reduce the size of the tiles a little (cf. Steam Wishlist Discount Notifier).

[Lacro59]

I will rework the UI when Playnite 11 is released.