add observer on pump deactivated to initialize pump status

[kskandis]

This resolves Issue Home View shows "No Pod" or "Signal Loss" despite insulin delivery system removal

283

Tested Omnipod and Medtronics on Simulator

[bjornoleh]

Merging with two approvals

Great job, @kskandis!

[marionbarker]

Testing after merge for completeness.

Status

• Success for Pods
• Success for MDT

Configuration

• iPhone SE iOS 17.5.1
• Trio dev, commit 9654d70a

Testing

• Add Omnipod DASH
  • Deactivate pod and see No Pod on main screen
  • Switch to other delivery and see Add pump on screen
• Add Medtronic pump, succeeds
  • Delete Medtronic pump and see Add pump on screen.