Canvas: Handle dashboard scenes edit state

[nmarrs]

The next generation of grafana dashboards based on scenes has a new editing toggle. Ideally canvas editing status should adhere to this and not be editable when the dashboard is not in edit mode

To make this work seamlessly I think that we will need to be able to subscribe to dashboard editable state inside of panels and react accordingly on every editable state change

See this slack thread for additional context

Screen.Recording.2024-05-15.at.5.11.35.PM.mov

Related to #87883 + #87446