codemirror: Update packages and add undo/redo to search query input
Created by: fkling
Fixes #35553 (closed) Closes #35537 (closed)
CodeMirror has been updated to v0.20, which introduces a new package structure (and other changes) as outlined here: https://discuss.codemirror.net/t/release-0-20-0/4302
This PR also introduces proper undo/redo to the search query input by adding the corresponding extension and keymaps.
Before and after:
https://user-images.githubusercontent.com/179026/168838036-2125c78f-8bec-4ac3-bded-e36f04044969.mp4
Test plan
Manual testing. Go to the homepage, type any input and press undo (e.g. ctrl-z). Go to any Notebook and add a new Markdown block.
App preview:
Check out the client app preview documentation to learn more.