Add a device.pipeline.deployed event to track device state changes from the device perspective

[cstns]

Description

Add a device.pipeline.deployed
Alter the ui to include this event in the device timeline
fix transition mode causing the loader and timeline to be present at the same time on the page

Related Issue(s)

part of #5111

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• Includes a DB migration? -> add the area:migration label

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.27%. Comparing base (ebe91bb) to head (b79bb29).
Report is 11 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #5149   +/-   ##
=======================================
  Coverage   78.26%   78.27%           
=======================================
  Files         339      339           
  Lines       15985    15989    +4     
  Branches     3697     3698    +1     
=======================================
+ Hits        12511    12515    +4     
  Misses       3474     3474           

Flag	Coverage Δ
backend	78.27% <100.00%> (+<0.01%)	⬆️

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