No On Hover Behaviour on +'s in Input Actions Editor

Steps to reproduce:

1. Open a Unity Project
2. Create a new Input Action Asset via GameObject > Create > Input Actions
3. Open the Input Action Asset in Input Actions Editor by double clicking on it
4. Hover over the + symbols next to Action Maps header, Actions header, or each Action

Actual results: There is no On Hover Behaviour and it is not clear to the user that they are hovered over the +

Expected results: There is On Hover Behaviour that makes it clear to the user that they are hovering over the +

Reproducible with versions: 7000, 1.11.2, 1.3.0

Tested on (OS): Windows 11

Notes: 

• If there is an On Hover Behaviour, then it is so minimal that it is not noticeable.