Introduce MemoryEvents to monitor their usage

[lucasgomide]

Added comprehensive memory event emission across all memory classes and implemented tests to verify events are properly emitted during memory operations.

[lorenzejay]

nice, but can you add some logs for it on event_listener.py, take a look at how we logged knowledge:

@crewai_event_bus.on(KnowledgeRetrievalCompletedEvent)
        def on_knowledge_retrieval_completed(
            source, event: KnowledgeRetrievalCompletedEvent
        ):
            if not self.knowledge_retrieval_in_progress:
                return

            self.knowledge_retrieval_in_progress = False
            self.formatter.handle_knowledge_retrieval_completed(
                self.formatter.current_agent_branch,
                self.formatter.current_crew_tree,
                event.retrieved_knowledge,
            )

[lorenzejay]

nice, but can you add some logs for it on event_listener.py, take a look at how we logged knowledge:

@crewai_event_bus.on(KnowledgeRetrievalCompletedEvent)
        def on_knowledge_retrieval_completed(
            source, event: KnowledgeRetrievalCompletedEvent
        ):
            if not self.knowledge_retrieval_in_progress:
                return

            self.knowledge_retrieval_in_progress = False
            self.formatter.handle_knowledge_retrieval_completed(
                self.formatter.current_agent_branch,
                self.formatter.current_crew_tree,
                event.retrieved_knowledge,
            )

what would be great is highlighting the retrieved memory instances over there

[lucasgomide]

@lorenzejay that is exactly what I was planning to do. I decided to focus this PR solely on Memory Events.. I will open another PR logging the usage into the console very soon

[lorenzejay]

Nice work