Store signals after SPA navigation are losed

[aralroca]

Probably related to #207 but different

After each SPA navigation, the store is initialized again, losing the registered signals on existing components. During SPA is not unmounting the web components that didn't change, so if they already have registered store signals, then updating the store is not reactive to the web components anymore.

[aralroca]

The problem is that the subscription is re-created again and registering again the listeners:

brisa/packages/brisa/src/utils/signals/index.ts

Line 19 in deb2cd7

const subscription = createSubscription();

Something like this can solve the problem:

window.subscription ??= createSubscription();

The logic inside signals of each web component is in charge of cleaning the listeners of the store it had, so when browsing it is cleaned and the listeners of the components that have not changed are preserved.