Add magic line comments regex pattern as configuration for uncommentMagicCommands

[pblocz]

I found this issue that was closed and could not ask there. I am having the same use case, databricks uses a different magic line format, like:

# MAGIC %run ./another_notebook

When working with databricks connect locally, if I change that line to

#! %run ./another_notebook

It does work locally, but not when running on databricks.

A possible solution would be to expose the pattern of the magic line comments as configuration. I can see it hardcoded in
uncommentMagicCommands and it would be in line with the cell marker regular expressions already exposed as configuration