Shortcuts Window/Command Palette

[danirabbit]

Problem

We currently rely on tooltips and menu items to expose keyboard shortcuts, but:

• there's no centralized way to search actions
• Tooltips only work if you know about tooltips and are using an input that can show them (not touch)
• There may be keyboard shortcuts available that aren't associated with a tool item or menu item

Proposal

• [ ] A built-in feature to show keyboard shortcuts, either via a keyboard shortcut or via holding down the CTRL key
• [ ] Expose actions that don't have an accelerator?
• [ ] It should probably be automatically populated by adding action accels
• [ ] It should be searchable

Prior Art (Optional)

VS Code Command palette: https://code.visualstudio.com/docs/getstarted/userinterface#_command-palette

iPad OS/Vision OS keyboard shortcuts window: https://developer.apple.com/design/human-interface-guidelines/keyboards#iPadOS-visionOS

https://docs.gtk.org/gtk4/class.ShortcutsWindow.html