Kernel startup commands should be definable at the workspace level not just user.

[greazer]

Honestly, it seems like a mistake that the Jupyter Kernel Startup Commands apply at the user level only. This seems likely way too broad for common use-cases. Couldn't we have one that works at the workspace level?

I ask because my DS chat participant needs to run code whenever a kernel is started. However, the user may not want to use this particular chat participant with EVERY project they ever work on. The extension itself is smart enough to detect whether the needed code is registered when it starts up. This can kick in with new workspaces just as easy.