Alignment button options (align to artboard)

This popover menu is currently "coming soon".


We'd like to have a checkbox (off by default) called "To Artboard" which makes the alignment of all selected layers work in relation to the artboard rather than their collective bounding box.

There has also been [a request](https://discord.com/channels/731730685944922173/1134981447539761273/1216556761910345868) for letting the user choose a specific layer's bounding box to align all other layers to (meaning that chosen layer doesn't move, but the others do).

Potentially one more feature that would be handy is a way to choose between "deep" and "shallow" treatment of nested layers, where only the selected folders get aligned vs. each of their contents get aligned.

Comienza con el popover de alineación mostrado en el issue y confirma con los maintainers qué comportamiento propuesto está dentro del alcance. Define como terminado que exista una opción “To Artboard” implementada y desactivada por defecto, o un tratamiento acordado de los comportamientos adicionales de selección de capas y de capas anidadas, con el comportamiento de alineación resultante verificado.

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