iter_with_data (#13102)

# Objective

- Provide a way to iterate over the registered TypeData.

## Solution

- a new method on the `TypeRegistry` that iterates over
`TypeRegistrations` with theirs `TypeData`

---------

Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
Co-authored-by: Gino Valente <49806985+MrGVSV@users.noreply.github.com>

crates/bevy_reflect/src/type_registry.rs

@@ -406,6 +406,15 @@ impl TypeRegistry {
     pub fn iter_mut(&mut self) -> impl Iterator<Item = &mut TypeRegistration> {
         self.registrations.values_mut()
     }
+
+    /// Checks to see if the [`TypeData`] of type `T` is associated with each registered type,
+    /// returning a ([`TypeRegistration`], [`TypeData`]) iterator for all entries where data of that type was found.
+    pub fn iter_with_data<T: TypeData>(&self) -> impl Iterator<Item = (&TypeRegistration, &T)> {
+        self.registrations.values().filter_map(|item| {
+            let type_data = item.data::<T>();
+            type_data.map(|data| (item, data))
+        })
+    }
 }
 
 impl TypeRegistryArc {