Fixes to key errors in examples jupyter notebook and plot proc

[kj5248]

Description

Resolved issue of stellarator files not working in the example notebook due to the config not being added to the temporary directory. Added commented out lines that will allow user to run this if desired, default remains the large_tokamak file. Also added ST option (from regression input files).

Resolved issue with plot_proc key errors when using an ST. Involved making changes to variables so there is consistency between ST and LT files. Also had to add additional checks for CS coil in plot_proc file. Finally separated pfcoil_geometry into pf and cs so that in case of no CS would still work, especially as they didn't need to be a single function. Now all key errors for running ST's through plot proc are resolved.

Checklist

I confirm that I have completed the following checks:

• My changes follow the PROCESS style guide
• I have justified any large differences in the regression tests caused by this pull request in the comments.
• I have added new tests where appropriate for the changes I have made.
• If I have had to change any existing unit or integration tests, I have justified this change in the pull request comments.
• If I have made documentation changes, I have checked they render correctly.
• I have added documentation for my change, if appropriate.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 7.69231% with 24 lines in your changes missing coverage. Please review.
✅ Project coverage is 46.03%. Comparing base (e5f34c1) to head (65bc865).

Files with missing lines	Patch %	Lines
process/io/plot_proc.py	4.76%	20 Missing ⚠️
process/build.py	0.00%	2 Missing ⚠️
process/geometry/pfcoil_geometry.py	33.33%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3994      +/-   ##
==========================================
- Coverage   46.04%   46.03%   -0.02%     
==========================================
  Files         123      123              
  Lines       28962    28974      +12     
==========================================
+ Hits        13336    13337       +1     
- Misses      15626    15637      +11     

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