Bug - TreeView - keyboard navigation not working properly for certain variants

Describe the problem
Namely the treeview with separate expansion and selection, treeview with checkboxes, and treeview with actions.

This is tricky because typically Left and Right arrow keys will either expand/collapse a node if it's not expanded, or it'll traverse to the parent/first child if it is expanded. May be difficult to do that when we need to traverse left and right to go to/from the expansion toggle and the node checkbox/button or an action button.

Another issue may be that the tabindexes don't get updated correctly, or at least they don't seem to. Only the expansion toggles get their tabindex updates to or from -1 and 0. I was sort of expecting that pressing Right Arrow to go to the node content in the "separate selection and expansion" example would update the expand toggle to tabIndex of -1, meaning that if I tab out of the tree view then Shift + Tab back into it, the node content recieves focus, not the expanion toggle.

How do you reproduce the problem?
Provide steps to reproduce. A codesandbox demonstrating the problem is appreciated.

Expected behavior
A clear and concise description of the expected behavior.

Is this issue blocking you?
List the workaround if there is one.

Screenshots
If applicable, add screenshots to help explain the issue.

What is your environment?

• OS: [e.g. iOS]
• Browser [e.g. chrome, safari]
• Version [e.g. 22]

What is your product and what release date are you targeting?

Any other information?

Jira Issue: PF-91

Beginne mit den TreeView-Beispielen für getrennte Auswahl und Erweiterung, Kontrollkästchen und Aktionen und reproduziere das Tastaturverhalten in der verknüpften CodeSandbox. Verfolge Fokus- und tabindex-Änderungen bei der Verwendung von Left, Right, Tab und Shift+Tab; abgeschlossen ist die Aufgabe, wenn Navigation und Fokus-Rückkehr über alle drei Varianten hinweg konsistent funktionieren.