IA2: When using ToString, print instead of throw errors

[spectranaut]

See #213

When dumping the tree via a dump tree script, we should keep going even if we encounter an error

[spectranaut]

@alice, this is in draft because I can't decide if this utility function I added just makes it more illegible and I should just try and catch every time I call an API function...?

[alice]

Style: since this is internal to the library, it should be using snake_case.

That said, though, I think I agree with your qualms about this util function. It might be easier to have this take the exception and format a string (i.e. basically just do what line 33 is doing here), and then the calling code would be more like

std::string actions;

try {
  long count = this->nActions();
  for (int i = 0; i < count; ++i) {
    std::string name = this->getName(i);
    actions += " " + name;
  }
} catch (const std::exception& e)
  actions = exception_to_string(e)
}

return "Actions:" + actions;