Convert EMotionFX runtime uint32 -> size_t

This allows the EMotionFX runtime to compile with `/we4267` enabled, which
emits a warning when converting from `size_t` to a smaller type. All tests
for the runtime have been updated accordingly, and they pass.

In instances where a range-for loop could be used, or a std algorithm, that
was used instead of using `size_t numItems = vec.size()` and a for loop.

Casts to `uint32` were removed where possible. Some places remain, like in
the file formats.

Signed-off-by: Chris Burel <burelc@amazon.com>

Gems/EMotionFX/Code/Tests/Integration/CanAddSimpleMotionComponent.cpp

@@ -66,7 +66,7 @@ namespace EMotionFX
             entity->GetId(),
             AZ::ComponentTypeList{azrtti_typeid<Integration::EditorSimpleMotionComponent>()}
         );
-        EXPECT_TRUE(componentOutcome.IsSuccess()) << componentOutcome.GetError().c_str();
+        ASSERT_TRUE(componentOutcome.IsSuccess()) << componentOutcome.GetError().c_str();
 
         bool hasComponent = false;
         AzToolsFramework::EditorComponentAPIBus::BroadcastResult(