Log and kill geometry/propagation errors

[sethrj]

This replaces the "kill looping tracks" with an explicit kernel for killing tracks, and replaces a host-only "validate" for tracks being inside the geometry and having a valid material ID. It logs descriptions and error messages for each of these cases.

A follow-on PR will add internal error states to the geometry tracking so we can catch issues with the current ORANGE implementation.

See https://github.com/celeritas-project/celeritas/issues/687 .

[sethrj]

This was a bit of a half-baked idea, you're perfectly right about the looping track not being the same as a geometry error. Maybe we should just make this a "tracking cut" action? Should we print log messages immediately when the error occurs?

It also exposes some of the fragility in our implementation... there's still a test failure due to a hardcoded condition not being met...

[amandalund]

Yeah, a "tracking cut" or more generic kind of "track killer" action might make more sense, same with printing the whole error message immediately.

[sethrj]

OK I think I'm going to rework this: maybe a combination of

• a tracking cut action, plus
• a helper function that can choose between logging a message and throwing an exception on host

[sethrj]

I'm going to close this in favor of a fresh PR.