Fix binding energy for electron analyers

[oliwenmandiamond]

Fixes binding energy not correctly working as the energy mode was always set to KINETIC. Added better testing to catch this.

Instructions to reviewer on how to test:

1. Check tests pass
2. Check additional tests are enough.

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}

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.79%. Comparing base (ca8ec91) to head (511e97f).

Additional details and impacted files

@@                             Coverage Diff                              @@
##           simplify_electron_analyser_driver_reference    #1600   +/-   ##
============================================================================
  Coverage                                        98.79%   98.79%           
============================================================================
  Files                                              260      260           
  Lines                                             9456     9458    +2     
============================================================================
+ Hits                                              9342     9344    +2     
  Misses                                             114      114           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.