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/suspense/mod.rs

@@ -46,7 +46,7 @@ impl SuspendedFuture {
     pub fn new(task: Task) -> Self {
         Self {
             task,
-            origin: current_scope_id().expect("to be in a dioxus runtime"),
+            origin: current_scope_id().unwrap(),
             placeholder: VNode::placeholder(),
         }
     }