Call catch_panic in libherald public api

[GallagherCommaJack]

Panicking across ffi is undefined behavior. Since we almost certainly won't succeed in proving the code won't panic, we should just catch it.

[BaeoMaltinsky]

An easy fix for this is modifying the codegen to catch unwinding panics. If it comes to that I'm inclined to think the program should just crash, so this really just be for cases where we really can't just propagate or handle an error.

Edit: This will not work. Too many of our data structures rely on interior mutability so we can't unwind safely.