Change notebook parameters to snake case

Sets all parameters in the first cell of the notebooks to use snake case. This caused issues with parity tests between the old and new CLI.

Description

Instead of changing all variable names throughout the notebook this renames the variable in the first cell and adds a second cell to continue using the previous variable name.

Done to minimise the changes made and as the non-snake-case variables do make sense in some cases (e.g. variable name matching a key name).

How Has This Been Tested?

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Relevant Documents (optional)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Chore (non-code changes, e.g. comments, readme, grammar, etc...)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I added tests where appropriate.

Reviewers

@schmidtp @ahmedk @kluyvert

mentioned in merge request !940

I appreciate the effort to minimise the diffs, but I think we probably should change the variable names throughout the notebooks - it's more effort to review now, but means the notebooks are more readable.

Also, do check if we're using any of these names in the existing config. My validation script in !1076 (merged) can probably help with that.

Hmmm, could we run the tests with names properly changed?

I was under the impression there some functional reason it's tricky to rename them, but a small diff should probably not stop us.

@roscar Both Thomas and me would prefer to properly change argument names

changed milestone to %3.16.0

removed milestone %3.16.0

We decided to hold back on this for now, and exempt those parameter from tests.