Add Multi Selection for Tree Component

[Ri-gers]

It would be great to have a Tree variant where multiple items could be selected instead of a single one. For example you could check a checkbox next to a (root) node and then all children would be selected. Parent nodes could have a state like selected/not selected/indeterminate (somewhat similar to the Trees here: https://dominokit.com/solutions/domino-ui/v2/docs/data-table/tree-eager).
A usecase could be that you configure permissions for users - if you check a root node, a user is allowed to do everything, if only a child is checked in the Tree, they can only perform a subaction etc.