[feature-request] [jupyter] support entering a value inline, with the web standard function `prompt`

[NaitLee]

With Jupyter with ipykernel, the notebook has an input box for the Python input function:

In Deno there’s the web standard prompt, for the same purpose as input in my mind, but with Deno as a Jupyter kernel it simply returns null instead: Same for Jupyter console:

It could be better to put this function in use for Jupyter notebook, just like its behavior in Deno console and web browser :)

[zph]

I'm also interested in this functionality for deno's jupyter kernel.

Problem Statement

Add prompt and input handling in Deno’s Kernel for Jupyter Notebook integration.

The experience should match what happens in a python based Jupyter Notebook when using prompt or input functions.

Code Tracing

Where handler lives in both deno + excxr (the source for deno's jupyter integration)

Deno: https://github.com/denoland/deno/blob/main/cli/tools/jupyter/server.rs#L347 Evcxr: https://github.com/evcxr/evcxr/blob/main/evcxr_jupyter/src/core.rs#L202 and https://github.com/evcxr/evcxr/blob/main/evcxr_jupyter/src/core.rs#L217

Handling allow_stdin is how this is done in Jupyter and the message itself will look like:

{"user_variables":[],"code":"1\n","silent":false,"allow_stdin":true,"store_history":true,"user_expressions":{}} ]

It's beyond my current proficiency in Rust to implement and port over from excxr, but I'm happy to test it out if someone else puts up a PR.