Add EBW/ECRH coupling efficiency graph plotting functionality

[chris-ashe]

This pull request adds a new plot to visualize the coupling efficiency of Electron Bernstein Waves (EBW) and Electron Cyclotron Resonance Heating (ECRH) as a function of the toroidal B-field. The implementation includes the creation of a new plotting function, integration of this plot into the main plotting workflow, and necessary imports and resource management updates. Additionally, there is a minor correction in the calculation of the electron cyclotron frequency.

New EBW/ECRH Coupling Efficiency Plot Integration:

• Added a new function plot_ebw_ecrh_coupling_graph to plot_proc.py that generates a plot of EBW and ECRH coupling efficiency versus the on-axis toroidal B-field for the first three harmonics, including both O-mode and X-mode for ECRH. The plot is styled with different colors and line styles for clarity.
• Integrated the new plot into the main plotting workflow by:
  • Adding a new figure (fig26/page26) for the plot.
  • Calling the new plotting function within main_plot and saving/closing the figure in the appropriate places.
  • Passing the new figure throughout the plotting pipeline.
• Imported ElectronBernstein and ElectronCyclotron from process.current_drive to support the new plotting function.

---

🐛 Bugs

• Removed unnecessary division by 1.0e19 in the calculation of the electron cyclotron frequency in electron_cyclotron_freethy. This caused the EC to always never couple 🤯

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 3.33333% with 58 lines in your changes missing coverage. Please review.
✅ Project coverage is 45.99%. Comparing base (26bfc59) to head (c4eacba).

Files with missing lines	Patch %	Lines
process/io/plot_proc.py	3.38%	57 Missing ⚠️
process/current_drive.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3984      +/-   ##
==========================================
- Coverage   46.03%   45.99%   -0.05%     
==========================================
  Files         123      123              
  Lines       28964    28998      +34     
==========================================
+ Hits        13335    13337       +2     
- Misses      15629    15661      +32     

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[j-a-foster]

Happy with plot addition.