[V2] Improve WhenVisible component to merge data and params props for a more flexible API

[PedroAugustoRamalhoDuarte]

This PR fixes #2025

Enhancements

• Merge data and params props:
  This PR introduces a more flexible API that merges the data and params props. Now, you can pass both in a single configuration like this:

  <WhenVisible fallback="Loading..." data={["todos", "pagy"]} params={{
    data: {
      teste: true,
      page: pagy.page + 1,
    },
    preserveUrl: true,
  }} />
  

• Make children optional in WhenVisible:
  Which enhances use cases like InfiniteScroll. Here’s an example:

  <WhenVisible fallback="Loading..." params={{
    data: {
      page: pagy.page + 1,
    },
    only: ["todos", "pagy"],
    preserveUrl: true,
  }} />