🐛 `TreeViewItem` content overflow

[S0NN1]

Describe the bug
Using a Text widget with very long text in the content attribute of a TreeViewItem makes the text overflow.

To Reproduce
Steps to reproduce the behavior:

1. Create a ThreeView with ThreeViewItems containing Text widgets in the content attribute wider than the current window size.
2. See text cut-off.

Expected behavior
The ThreeViewItem should let the user define a fixed height or adapt to content size.

Screenshots