Updates for analyses in internal variability notebook

[Tianchi-Liu]

Description of PR

Backend changes needed to support the addition of 0.8 and 1.2 as options for internal variability analyses

Summary of changes and related issue

• TODO
  • Update data
    • Run util/generate_gwl_tables_unc.py
    • Review output data/gwl_1981-2010ref_EC-Earth3_ssp370.csv for the addition of 0.8 and 1.2 columns
  • Check for need to update explore/uncertainty.py - gwl_times defined in line 734 should have the same rows, but additional columns for 0.8 and 1.2

Relevant motivation and context

WL 0.8 and 1.2 were added to the table gwl_1981-2010ref.csv. Internal variability analyses also rely on table gwl_1981-2010ref_EC-Earth3_ssp370.csv. This PR adds WL 0.8 and 1.2 to that as well.

Type of change

• 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 not work as expected)
• This change requires a documentation update

Definition of Done Checklist

Practical

• 80% unit test coverage
• Documentation
  • All functions/adjusted functions documented in the readthedocs.
  • Documentation is pushed
• Complex code commented
• Naming conventions followed
  • Helper functions hidden with _ before the name
• Context of function is clearly provided
  • Intent of function is provided
  • How to test, so that it is not siloed on scientists and anyone can review
  • Appropriate manual testing was completed
• Any notebooks known to utilize the affected functions are still working
• Linting completed and resolved

Conceptual

• Doesn't replicate existing functionality
• Aligns with general coding standard of existing functions
• Matches desired functionality from users/scientists