`Shift+Del` doesn't work as shortcut for Delete.

Is your feature request related to a problem? Please describe.
In Tiled, I can change the keybinding of "delete" from DEL to SHIFT+DEl, but without any effect on deleting Objects.

I talked with @eishiya on Discord on 27.03.2022 (16:28) about the problem, they can confirm that and added further observations:

Set my Delete to Shift+Del
Layers panel: both Del and Shift Del will delete a layer
Properties panel: ditto for custom properties
Map editor, selected tiles: Neither Del nor Shift+Del delete tiles

Set to Ctrl+Del
Del/Shift+Del/Ctrl+Del will delete layers and properties still
Ctrl+Del and nothing else deletes tiles, as expected.

So, I can reproduce Abo's experience with the Shift+Del Delete shortcut. I guess Del is hard-coded for deleting layers and properties, and the configurable shortcut is only for Edit > Delete (i.e. objects and tiles).

Describe the solution you'd like
Being flexible with using dfferent modifiers for such keybindings, like SHIFT + DEL, although Shift is used for Tools.

Describe alternatives you've considered
Being not so clumsy and try to avoid the "DEL" key to prevent deleting stuff accidentally.
Or using CTRL+DEL, but this feels weird.

Start by reproducing the shortcut behavior in Tiled's map editor using the Delete, Shift+Delete, and Ctrl+Delete bindings described in the issue. Trace the map editor's object and tile deletion actions, then verify that a configurable Shift+Delete binding deletes selected objects and tiles while the existing layer and property behavior remains correct.