Fix SolutionInform dict access

[ewu63]

Purpose

Realized that we effectively broke sol_inform in #437 because we were previously using a dict. This is now fixed by implementing __getitem__, however I wonder if we should yank or make a post-release? This oversight is probably going to break pretty much everyone's code...

Expected time until merged

ASAP

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

Checklist

• I have run flake8 and black to make sure the Python code adheres to PEP-8 and is consistently formatted
• I have formatted the Fortran code with fprettify or C/C++ code with clang-format as applicable
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 74.89%. Comparing base (dd1e3bc) to head (0e006d4).
⚠️ Report is 9 commits behind head on main.

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #450       +/-   ##
===========================================
- Coverage   86.19%   74.89%   -11.31%     
===========================================
  Files          24       24               
  Lines        3413     3418        +5     
===========================================
- Hits         2942     2560      -382     
- Misses        471      858      +387     

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[ewu63]

Superseded by #451.