[Core] Entity diff calculation only on resync

[yaelibarg]

Description

What - made the entity diff calculation only on resync

Why - most of the events that are not resync dont change alot of entities, so its not worth searching the entity and checking diff on it

How - added a check if event.event_type == EventType.RESYNC:

Type of change

Please leave one option from the following and delete the rest:

• New feature (non-breaking change which adds functionality)

All tests should be run against the port production environment(using a testing org).

Core testing checklist

• Integration able to create all default resources from scratch
• Resync finishes successfully
• Resync able to create entities
• Resync able to update entities
• Resync able to detect and delete entities
• Scheduled resync able to abort existing resync and start a new one
• Tested with at least 2 integrations from scratch
• Tested with Kafka and Polling event listeners
• Tested deletion of entities that don't pass the selector

[Tankilevitch]

lgtm