perf(reactivity): improve reactive effect memory usage (#4001)

Based on #2345 , but with smaller API change

- Use class implementation for `ReactiveEffect`
- Switch internal creation of effects to use the class constructor
- Avoid options object allocation
- Avoid creating bound effect runner function (used in schedulers) when not necessary.
- Consumes ~17% less memory compared to last commit
- Introduces a very minor breaking change: the `scheduler` option passed to `effect` no longer receives the runner function.

packages/runtime-core/src/compat/global.ts

@@ -1,7 +1,6 @@
 import {
   isReactive,
   reactive,
-  stop,
   track,
   TrackOpTypes,
   trigger,
@@ -575,7 +574,7 @@ function installCompatMount(
         // stop effects
         if (effects) {
           for (let i = 0; i < effects.length; i++) {
-            stop(effects[i])
+            effects[i].stop()
           }
         }
         // unmounted hook