poster prop is not declarative (does not update poster when URL changes)

Hello Cloudflare team,

We have a use case where we are using an external 'video picker' list to select a video they want to watch.

Once they click it, we update the props going to the `` component, including the `src` and `poster` props.

The `src` prop seems to take effect, because starting the video does in fact play the selected video, however the poster does not change.

It looks like it's an intended behavior due to the `useMemo` implementation without dependencies here:
https://github.com/cloudflare/stream-react/blob/fda143fde6e235706ae14afc9dc919a11374c15b/src/useIframeSrc.tsx#L53-L59

Which says you can use the SDK to make the changes... but I don't see how.

Thanks in advance - we're hoping to switch to Stream from a competitor but this is blocking our implementation :)

Empieza leyendo src/useIframeSrc.tsx alrededor de las líneas 53-59, especialmente el comportamiento de useMemo descrito en el issue. Reproduce el caso cambiando la prop poster del componente Stream junto con src y, después, verifica que el poster mostrado se actualice cuando cambie la URL.

Escrito por el modelo de indexación a partir del texto del issue.