Refactor script into export_staircase_data.py

[joeyshuttleworth]

Description

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Testing

• Testing is done automatically and codecov shows test coverage
• This cannot be tested automatically

Documentation checklist

• I have updated all documentation in the code where necessary.
• I have checked spelling in all (new) comments and documentation.
• I have added a note to RELEASE.md if relevant (new feature, breaking change, or notable bug fix).

[MichaelClerx]

@joeyshuttleworth could you fill in the "description" bit for this? What was it meant to achieve?

[MichaelClerx]

@joeyshuttleworth what was this PR meant to do? Should I try fixing the issues and merging it?

[joeyshuttleworth]

We were trying to make a script which would only export the data, without running QC on everything. I believe this has since been abandoned and everyone's just using "run_herg_qc.py"