Feature request: Replace the query editor with Monaco

[AndrewRayCode]

The core vscode editor and its shortcuts are quite versatile, and appear to be a more polished superset of the current querybook editor. It has features the querybook editor could benefit from, like multiple cursor support.

[czgu]

I think multiple cursor support is available currently with codemirror? My personal preference would be to upgrade to https://codemirror.net/6/ since it is more modular and (potentially) simpler to upgrade