When using Jupyter (instead of raw kernels) create Kernelspecs in a custom directory

[DonJayamanne]

Today we create the kernelspec json files in the global known Jupyter kernels directory.
This causes a few issues:

• Write access Failed to change kernel [NoPermissions (FileSystemError): Unable to write file #5494
• Users edit these kernelspecs (but its not meant for users)
• Maintenance issues
• Code is a little complex (as we need to identify what we created vs what we created as a mapping for custom kernels created by users)
• There have been others

If we create kernelspecs in a custom directory that user isn't aware of:

• We know that these are created by us
• These need not EVER be displayed in the kernel picker
• We can blow these away anytime as we don't have to worry about users editing them

Solution

• Create these in a folder specific to the extension version (i.e. within the extension directory)

[rebornix]

@DonJayamanne can you please provide detailed steps of what to test?

[rchiodo]

I believe this is a dupe of another. I already verified the kernelspecs are created in the temp folder under the extension.

[rchiodo]

Duh the dupe is in this issue. THe one I verified earlier:
#5494