Fix mv env header buttons to function.

- Requires the il flag
- Fires correct event updates to show/hide the machine view UI
- Adds a test for the correct events.
- Update to make sure the header is drawn in the new state world.
- Update the CSS to move the machine view panel next to the sidebar.

QA
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Load the GUI with :flags:/il/mv and click back/forth on the buttons in the
control for Service/Machine views.