Replace monaco editor with codemirror

[ravenac95]

I think we should explore using code-mirror as the editor for things like models. It's the same editor that we have on our notebooks (from marimo) and it is apparently faster and more extensible than monaco.

Other niceties:

• Rendering multiple editors on the same page is better because it doesn't have global state like monaco (might be necessary if/when we start showing multiple pieces of code at once of different language types).
• Works well on mobile
• Lighter weight

Some resources

• https://blog.replit.com/code-editors
• https://sourcegraph.com/blog/migrating-monaco-codemirror

[linear[bot]]

OSO-1238

[ryscheng]

@IcaroG I think this is done right?

[IcaroG]

Yes! Thank you