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/events.rs

@@ -397,7 +397,7 @@ impl<Args: 'static, Ret: 'static> Callback<Args, Ret> {
         ));
         Self {
             callback,
-            origin: current_scope_id().expect("to be in a dioxus runtime"),
+            origin: current_scope_id().unwrap(),
         }
     }
 
@@ -409,7 +409,7 @@ impl<Args: 'static, Ret: 'static> Callback<Args, Ret> {
                 as Rc<RefCell<dyn FnMut(Args) -> Ret>>));
         Self {
             callback,
-            origin: current_scope_id().expect("to be in a dioxus runtime"),
+            origin: current_scope_id().unwrap(),
         }
     }
 
@@ -427,7 +427,7 @@ impl<Args: 'static, Ret: 'static> Callback<Args, Ret> {
                     value
                 })
             })
-            .expect("Callback must be called from within the dioxus runtime")
+            .unwrap()
         } else {
             panic!("Callback was manually dropped")
         }