Allow use of number hotkeys when a tile layer is not selected

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_Using Tiled 1.7.2, Linux._

__Problem:__

I tried to bind the number keys to the object shape tools (CreateRectangleObjectTool, CreatePointObjectTool, etc.) and was very confused why they worked just fine in the Tile Collision Editor with a tileset open, but silently failed to work with a tile*map* open and an object layer selected.

After a bit of searching I found that [the number keys recall your saved tile stamps when editing a tile layer](https://doc.mapeditor.org/en/stable/manual/keyboard-shortcuts/#when-a-tile-layer-is-selected).

__Feature Request:__

Make the recall-tile-stamp bindings on the number keys not steal inputs outside of their context (tile layer selected)

__Other Info:__

* Binding something to the number 1 key works everywhere except the tilemap view.
* Binding a built-in tool to the number 1 key fails silently in the tilemap view.
* Binding any action or a custom tool to the number 1 key fails and prints "`QAction::event: Ambiguous shortcut overload: 1`" to the console, _every other time_ I press the key or continuously if I hold the key down.

Reproduce the shortcut behavior in the tilemap view with an object layer selected, then trace how saved tile-stamp bindings are handled for a selected tile layer. Done means number-key bindings for tools or actions work outside tile-layer editing without producing ambiguous shortcut warnings.

Written by the indexing model from the issue text.