Tree global selection listener not triggered when selecting TreeItems appended to the Tree root

[vegegoku]

Describe the bug
A selection listener added to the Tree root will not be triggered from TreeItem directly appended to the Tree.

To Reproduce

Tree.<String>create("Menu")
                            .setSearchable(true)
                            .addSelectionListener((source, selection) -> {
                                DomGlobal.console.info("Item selected");
                            })
                            .appendChild(TreeItem.create("Item 1"))
                            .appendChild(TreeItem.create("Item 2"))

The selection listener wont be triggered.

Expected behavior
The selection listener should be executed and print the log message.