Use a single electron analyser detector

[oliwenmandiamond]

Fixes #ISSUE

Instructions to reviewer on how to test:

1. Do thing x
2. Confirm thing y happens

Checks for reviewer

• Would the PR title make sense to a scientist on a set of release notes
• If a new device has been added does it follow the standards
• If changing the API for a pre-existing device, ensure that any beamlines using this device have updated their Bluesky plans accordingly
• Have the connection tests for the relevant beamline(s) been run via dodal connect ${BEAMLINE}

[fajinyuan]

agree with these changes

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.14%. Comparing base (e0d5a17) to head (44cade9).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1803   +/-   ##
=======================================
  Coverage   99.14%   99.14%           
=======================================
  Files         288      288           
  Lines       10937    10940    +3     
=======================================
+ Hits        10843    10846    +3     
  Misses         94       94           

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[oliwenmandiamond]

This is currently blocked by bluesky/bluesky#1978