[MISP] Adds propagate labels from Event to Attribute option #3495

[Ltheyoung]

Currently the Attributes tags take precedence over the Events tags (if attribute has tags)

This commit allows for the option to allow the labels that are present on an Event (OpenCTI Reports) to apply on top of the labels set by the Attributes (Observables and/or Indicators). While not changing behaviour by introducting a setting that defaults to the previous behaviour.

Proposed changes

• Add setting for this new feature with default of old behaviour
• Add the Event labels to the Attribute labels when setting is set to true, otherwise keep old behaviour

Related issues

• [MISP] - Propagate event labels to entities extracted from the event  #3495

Checklist

• I consider the submitted work as finished
• I tested the code for its functionality using different use cases
• I added/update the relevant documentation (either on github or on notion)
• Where necessary I refactored code to improve the overall quality

Further comments

This would be my first PR to this project any guidance where needed is appreciated.