Better expect error messages (#2629)

* Replace expect error messages

* Change message

* Create RuntimeError struct

* Pass error through core methods

* Fix use of Runtime::current in signals package

* Fix tests

* Add #[track_caller] for better error output and fix maybe_with_rt

* provide a help message along with RuntimeError

---------

Co-authored-by: Evan Almloff <evanalmloff@gmail.com>

packages/core/src/scopes.rs

@@ -21,6 +21,7 @@ impl std::fmt::Debug for ScopeId {
         #[cfg(debug_assertions)]
         {
             if let Some(name) = Runtime::current()
+                .ok()
                 .as_ref()
                 .and_then(|rt| rt.get_state(*self))
             {