Add cost values to outputs

[yiwen-h]

Actually closes #93 this time!

Excel worksheets are now actual costs instead of activity duration in that year

[codecov]

Codecov Report

❌ Patch coverage is 70.00000% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.89%. Comparing base (ab4394f) to head (7725481).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
renal_capacity_model/process_outputs.py	71.42%	2 Missing ⚠️
renal_capacity_model/main.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #154      +/-   ##
==========================================
+ Coverage   85.75%   85.89%   +0.14%     
==========================================
  Files           9        9              
  Lines         688      695       +7     
  Branches       78       79       +1     
==========================================
+ Hits          590      597       +7     
  Misses         89       89              
  Partials        9        9              

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[morganle-48]

Looks good - it ran for me and the output looks sensible for the unit I'm testing! Thanks