Restructure remaining process package into process/core

[timothy-nunn]

No description provided.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 86.33880% with 25 lines in your changes missing coverage. Please review.
✅ Project coverage is 46.88%. Comparing base (73e929a) to head (04e3674).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
process/core/io/plot_proc.py	23.52%	13 Missing ⚠️
process/core/io/mfile_comparison.py	0.00%	2 Missing ⚠️
process/core/io/plot_scans.py	0.00%	2 Missing ⚠️
process/core/io/write_new_in_dat.py	0.00%	2 Missing ⚠️
process/core/io/costs_bar.py	0.00%	1 Missing ⚠️
process/core/io/costs_pie.py	0.00%	1 Missing ⚠️
process/core/io/mfile_to_csv.py	0.00%	1 Missing ⚠️
process/core/io/plot_sankey.py	0.00%	1 Missing ⚠️
process/core/io/plot_solutions.py	0.00%	1 Missing ⚠️
process/core/io/sankey_funcs.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4108   +/-   ##
=======================================
  Coverage   46.88%   46.88%           
=======================================
  Files         136      136           
  Lines       29253    29255    +2     
=======================================
+ Hits        13715    13717    +2     
  Misses      15538    15538           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.