Move version in event handler

[ciarams87]

Proposed changes

Problem: The version variable is used by handler to track generated config versions. It is part of the handler config, which means we expect it to be configurable when creating the handler. However, it is not configurable, so should not be part of the config.

Solution: Refactor the handler so that version is part of the handler, not its config

Testing: Ensured all tests still pass successfully and manual verification of the config version file

Closes #1416

Checklist

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• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

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