[Runtime] Implement Full `watchEffect` Functionality in Vue Vapor

[LittleSound]

The current implementation of effect within the vue-vapor project does not fully conform to the standard watchEffect behavior, particularly lacking in comprehensive flush timing options.

We aim to align vue-vapor's watchEffect with the standard version by introducing detailed flush options (pre, post, sync). A fully realized flush mechanism will facilitate the implementation of the beforeUpdate directive lifecycle hook.
In addition, we plan to introduce a new onEffectCleanup API analogous to onScopeDispose, which will aid in implementing dynamic arguments for v-on. first, extend watchEffect in the runtime-vapor package. If necessary later, extract it to the reactivity package.

[1049906948]

强