UI refresh todo-notes

[lawik]

Things that may not be obvious but need attention and has intentionally been left for later passes:

• Device listing action menu needs hover states and making interactivity more obvious
• Device listing: health column (should indicate deviations from expected values, and any alarms)
• Device listing: metrics column
• Device listing: Firmware, shield should indicate updates enabled AND whether put in penalty box
• Device listing: Bulk Actions, add "Assign deployment"
• All list views: Empty states when nothing is there
• Sidebar: Purple gradient on border missing

[lawik]

Feel free to add stuff in your own comments if you work on this.