Reverse reaction (super-elastic) electron collision reaction

[BangShiuh]

Changes proposed in this pull request

The reverse reaction rate of electron collision reaction is added. The reverse rate is calculated super-elastic formula. In the test, a reversible elastic reaction is used for testing purpose only. The reverse rate is the same as the forward rate if the threshold energy is zero.

• Use commits from @speth for modification of the reverse rate.
• Make electron collision plasma reaction (ECPR) reversible.
• Add test for ECPR.
• I will add the example later

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

Cantera/enhancements#192

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

Checklist

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

[codecov]

Codecov Report

Attention: Patch coverage is 85.48387% with 9 lines in your changes missing coverage. Please review.

Project coverage is 74.41%. Comparing base (d095f70) to head (46856db).

Files with missing lines	Patch %	Lines
src/kinetics/ElectronCollisionPlasmaRate.cpp	79.16%	2 Missing and 3 partials ⚠️
src/kinetics/BulkKinetics.cpp	89.47%	0 Missing and 2 partials ⚠️
src/kinetics/InterfaceKinetics.cpp	84.61%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1854   +/-   ##
=======================================
  Coverage   74.40%   74.41%           
=======================================
  Files         386      386           
  Lines       53630    53651   +21     
  Branches     9065     9071    +6     
=======================================
+ Hits        39905    39925   +20     
+ Misses      10653    10652    -1     
- Partials     3072     3074    +2     

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