Delete commands (`deleteLeft`, `deleteRight`) don't work in dialogs

Issue Type: <b>Bug</b> Steps to reproduce 1. Add the following to keybindings.json ``` { "key": "ctrl+h", "command": "deleteLeft" }, ``` 2. Verify it works in file focus 3. Execute it in a dialog focus (find or command palette) and get unexpected result *Expectation*: A character from the focused dialog should be deleted *Actuality*: A character from the last editor focus is deleted When I search the binding for my `backspace` key in `Preferences: Open Keyboard Shortcuts`, it shows that `backspace` is bound to `deleteLeft`. The aforementioned result is all the more unexpected considering that the backspace key does what I expect whereas ctrl+h doesn't, even though they are "supposedly" bound to the same command. VS Code version: Code 1.66.1 (8dfae7a5cd50421d10cd99cb873990460525a898, 2022-04-06T14:50:12.141Z) OS version: Windows_NT x64 10.0.22000 Restricted Mode: No <details> <summary>System Info</summary> |Item|Value| |---|---| |CPUs|11th Gen Intel(R) Core(TM) i7-1185G7 @ 3.00GHz (8 x 2995)| |GPU Status|2d_canvas: enabled<br>canvas_oop_rasterization: disabled_off<br>direct_rendering_display_compositor: disabled_off_ok<br>gpu_compositing: enabled<br>multiple_raster_threads: enabled_on<br>oop_rasterization: enabled<br>opengl: enabled_on<br>rasterization: enabled<br>raw_draw: disabled_off_ok<br>skia_renderer: enabled_on<br>video_decode: enabled<br>video_encode: enabled<br>vulkan: disabled_off<br>webgl: enabled<br>webgl2: enabled| |Load (avg)|undefined| |Memory (System)|15.71GB (5.82GB free)| |Process Argv|--crash-reporter-id b6b63ffd-30a1-4a6a-ad59-7dbdd7de2c9f| |Screen Reader|no| |VM|0%| </details><details><summary>Extensions (39)</summary> Extension|Author (truncated)|Version ---|---|--- project-manager|ale|12.5.0 tsl-problem-matcher|amo|0.6.2 github-markdown-preview|bie|0.2.0 markdown-checkbox|bie|0.3.2 markdown-emoji|bie|0.2.1 markdown-footnotes|bie|0.0.7 markdown-preview-github-styles|bie|1.0.1 markdown-yaml-preamble|bie|0.1.0 gitignore|cod|0.7.0 d…