Add a max_events setting.

[pshriwise]

Description

Fixes #2944

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)

[pshriwise]

The value in particle_data.h was an int, curious what others think about changing this to uint32_t for the new setting.

[paulromano]

Thanks for adding this @pshriwise!