SQL cell (and others?) in jupyter engine and ipython kernel

It might make sense for us to leverage cell magics to support (eg) a native sql cell in the same way that knitr does it.

Pros:

• it's a popular request
• it would us get closer to matching the behavior in the knitr engine

Cons:

• it would make it even harder for beginners to reason about what engine is responsible for what execution. Specifically, cell magics are specific to the ipython kernel
• it would not solve the problem for other jupyter kernels

If we continue to increase the ways in which different engines interpret {language} cells, I think it would be a good idea for quarto to be able to explain who runs what cells. I can imagine a TypeScript API that could do so.