QTree v-model:selected to return the entire node

[Tofandel]

Currently the selected v-model of the QTree uses the id of the node to determine if its selected and returns that id

It's not always very useful and having the entire node might make more sense in some cases but with just the id we have to iterate recursively on the nodes to find the selected

I'd like to add a prop to change this behaviour

I will make a PR, I just would like to know the preferred implementation

• a single prop to change selected from id to the full node
• 2 props to pass a comparison function for the selection and another function to return a value from the node when selecting
• pass a second argument being the full node to the emit value of the update:selected and keep id as the selection value but at least makes the node available in the event without needing to search for it
• a mix of 2 and 3, only one comparison function and update the event to include the node as well so that the @update:selected acts as the second function

The 2nd option is more flexible but more verbose, the 1st I think already covers most of the cases possible with the second option
The 3rd option is the simplest, it only changes one line, but may not cover all use cases

I like the second option because it also allows you to just pass a comparison function to just check properties on the node like (node) => node.isSelected indifferently of the selected prop as well