Deduplicate reactive scope updates/Reset subscriptions on reruns/fix use memo double update (#2506)

* deduplicate effect updates

* only subscribe to signals read in the current run of reactive scopes

* subscribe to memo reads after recomputing the value

packages/core/src/scope_context.rs

@@ -1,4 +1,5 @@
 use crate::{innerlude::SchedulerMsg, Element, Runtime, ScopeId, Task};
+use generational_box::{AnyStorage, Owner};
 use rustc_hash::FxHashSet;
 use std::{
     any::Any,
@@ -91,6 +92,17 @@ impl Scope {
         })
     }
 
+    /// Get the owner for the current scope.
+    pub fn owner<S: AnyStorage>(&self) -> Owner<S> {
+        match self.has_context() {
+            Some(rt) => rt,
+            None => {
+                let owner = S::owner();
+                self.provide_context(owner)
+            }
+        }
+    }
+
     /// Return any context of type T if it exists on this scope
     pub fn has_context<T: 'static + Clone>(&self) -> Option<T> {
         self.shared_contexts