use background thread on kernel to gather variable information

[amunger]

example: https://insiders.vscode.dev/github.com/microsoft/vscode-jupyter/blob/main/src/standalone/chat/extesnion.ts#L82-L100

[amunger]

@DonJayamanne can you help me with a couple questions:

• Our namespaced built-ins aren't available in the scope of the bg thread, does that mean that normal built-ins are ok to use?
• "../../standalone/api/kernels/backgroundExecution" imported in restricted zone. Only modules from ./src/platform and ./src/telemetry can be imported into ./src/kernels.
  • can we move this hleper into platform?

[DonJayamanne]

Yes to both,
Though I'm not sure why first isn't working. it should
Perhaps its the way the python code is structured,
If i recall correctly we to send multiple requests (the first few setup the namesapces and global functions),
instead of sending multiple requests, we might want to send one single request,
Else a function created in one request might not be available to the other request (after all the scope is different as each run in a function scope in different threads).