Restore set compare hook (#2287)

* restore set compare hook

* fix use_set_compare doc example

* add a hook to compare a value with a set

* implement partialeq for SetCompare

* export the new hook

* fix the use_set_compare hook

packages/signals/src/lib.rs

@@ -16,8 +16,8 @@ pub use read_only_signal::*;
 mod map;
 pub use map::*;
 
-// mod comparer;
-// pub use comparer::*;
+mod set_compare;
+pub use set_compare::*;
 
 mod memo;
 pub use memo::*;