Toolbar: Add toolbar spacer

Toolbar could use a `toolbar_spacer()` which could be a space, dividing line OR a nav_spacer() style "push the things over".

For example:

<img width="348" height="54" alt="Image" src="https://github.com/user-attachments/assets/6a348803-e73c-4db1-bcb0-bf867f2dc6d8" />






