Implement tally filter for filtering by reaction

[paulromano]

Description

This PR introduces a new tally filter that allows scores to be filtered based on the reaction type. This is useful for specialized scores that don't directly represent a reaction rate, e.g., if you are tallying heating or secondary particle production.

Closes #3230

Checklist

• I have performed a self-review of my own code
• I have run clang-format (version 15) on any C++ source files (if applicable)
• I have followed the style guidelines for Python source files (if applicable)
• I have made corresponding changes to the documentation (if applicable)
• I have added tests that prove my fix is effective or that my feature works (if applicable)

[GuySten]

How does this filter handle endf sum rules?
For example, is using "(n,nonelastic)" legal?

[paulromano]

@GuySten Great point, right now it won't work for summation reactions but I think that shouldn't be too hard to implement -- let me see what I can do.

[paulromano]

@GuySten I just implemented the capability to handle summation reactions like (n,nonelastic)

[GuySten]

For neutrons, 'total' means mt=1 while for photons 'total' means mt=501.
I lean towards adding an incident particle field to this filter to prevent ambiguity.

I think that it is a bit unexpected that when tallying photon flux total will be empty.
What do you think?

[paulromano]

@GuySten I've just made some updates to deal with the photon total reaction (MT=501). Rather than having a separate filter by particle, now the behavior is that if the user passes "total" for a ReactionFilter, they get a warning saying that it is redundant and defaults to MT=1 but that that they should use (n,total) or photon-total to be explicit.

[GuySten]

Looks good to me!