Add server-side wrapper kernel

### Problem

Being able to use the pyodide kernel without a browser or nodejs would make it more testable.

### Proposed Solution

- use an `ipykernel.KernelBase` wrapper kernel
- potentially use a v8-in-python e.g. `pyminiracer`, etc.
- proxy the `DriveFS` stuff to a _real_ fs :scream:
- wrap `pyodide.wasm`, etc. inside `wasmer`
- use for testing, etc.
- proxy jupyter kernel messages into the wasm runtime

### Additional context

- discussed in the December 2022 JupyterLite workshop