Upgrade to @headlessui/react v2 and add support for selectedOption

[andreibarabas]

Currently, the select item components only support plain text, but if we want to add some complex UI in the dropdown, it's not possible because we need it to be text in the Select field.

With the new selectedOption render prop introduced by @headlessui, we could use the children of to render it's complex ui when the dropdown is expanded, and then add a selectedOptionText property to the SelectedItem to show in the bar

Something like