Tree: selection mode support

[jasdom]

Hi, we are replacing the old tree component with the one provided by @itwin/itwinui-react, and the previous implementation supported multiple selection modes that allowed the use of ctrl, shift and drag to select/deselect multiple nodes. Are there any plans to add support for a similar feature?

If support for such modes is not planned, we would at least be interested in shift+clicking nodes to select all nodes between the previous selection and the node that was shift+clicked.

[mayank99]

There are no immediate plans, but I think in the future we could look into supporting at least a subset of what you requested.

Recently we got another question about supporting similar functionality in TransferList: #2018

It would be nice to centralize this kind of logic to be used in Table, TransferList and Tree.