[Approved] Plasma 6 proposal: Remove or disable "Windowed widgets" by default

From kdeplasma-addons!315 (merged), I thought about the search category "Windowed widgets" and it came to me that this might not be very useful at all. This MR was specifically removing one widget (Calculator) from appearing in search results, so I thought maybe we should just do away with this category entirely.

Is there a use case that is fullfilled with having a windowed widget (where they were not really designed to be expanded or put inside of a window)? The one time I used the color picker in a windowed widget was painful for example, but by no fault of it's own - I don't think any widgets were designed this way. If you can think of a reason, maybe it should be disabled by default instead (or put very low in the priority list).

Edit: I just realized that it's the plasmoid's decision to be standalone, but the point still stands.