Add sensitivity analysis for tallies #3179
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Description
This PR adds tally to score sensitivity coefficients. The tally is useful to perform sensitivity and uncertainty analysis. This feature is based on development by @alhajri on eigenvalue sensitivity analysis.
N.B. Benchmarking the sensitivity tally is still ongoing and still needs lot of work. Folks can take a look to fix it and provide advice.
The feature is applicable to both criticality and fixed-source problems. However, my benchmarking is geared towards fixed-source applications. Usage requires to first run OpenMC to calculate the adjoint flux. Then use the adjoint flux in a second OpenMC run to tally the sensitivity coefficients. Details of how to calculate the adjoint flux in eigenvalue problems and how the sensitivity coefficients are calculated can be found in here
Checklist