Fix converting surface mechanisms that use a separate thermo data file

[speth]

Changes proposed in this pull request

• Read the surface input file before the "thermo" file so the full list of species for which thermo data will be known when the thermo file is read.
• Fix the summary printed at the end so the species count includes both bulk and surface phase species

If applicable, fill in the issue number this pull request is fixing

This fixes an issue that was originally reported in this Users' Group post

If applicable, provide an example illustrating new features this pull request is introducing

Checklist

• [x] The pull request includes a clear description of this code change
• [x] Commit messages have short titles and reference relevant issues
• [x] Build passes (scons build & scons test) and unit tests address code coverage
• [x] Style & formatting of contributed code follows contributing guidelines
• [x] The pull request is ready for review

[codecov[bot]]

Codecov Report

Merging #1637 (0fc24ea) into main (3a9bc6a) will decrease coverage by 0.01%. The diff coverage is 57.89%.

@@            Coverage Diff             @@
##             main    #1637      +/-   ##
==========================================
- Coverage   72.69%   72.68%   -0.01%     
==========================================
  Files         370      370              
  Lines       56298    56302       +4     
  Branches    20375    20403      +28     
==========================================
- Hits        40925    40923       -2     
+ Misses      12376    12371       -5     
- Partials     2997     3008      +11     

Files	Coverage Δ
interfaces/cython/cantera/ck2yaml.py	84.48% <57.89%> (-0.18%)	:arrow_down:

... and 4 files with indirect coverage changes

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more

[speth]

The failing linter test is expected -- the point was to test messy input with tabs and trailing spaces. I didn't think it was worth trying to add exclude rules, given this won't show up again unless there are modifications to this or other similar input files.