[Core] Add equality comparison operator to BatchElementError

[feltech]

What

Add equality operator to BatchElementError.

Why

This would be useful for tests, if nothing else.

ACs

• Given two different error objects (with different addresses) error1 == error2
• No temp comparison implementations remain in tests/etc
• Tests that compare BEEs (🐝) updated.
• != behaviour also tested if required but not if inherent in the language (C++/Python, create issue for TraitsData if were missing anything there)

Notes

Implement as member function to follow prior art

[foundrytom]

Remember to update ManagerTest.cpp

[foundrytom]

... and test_manager.py