refactor: Move events module to crewai.events (#3425)

refactor(events): relocate events module & update imports

- Move events from utilities/ to top-level events/ with types/, listeners/, utils/ structure
- Update all source/tests/docs to new import paths
- Add backwards compatibility stubs in crewai.utilities.events with deprecation warnings
- Restore test mocks and fix related test imports

docs/pt-BR/concepts/event-listener.mdx

@@ -44,12 +44,12 @@ Para criar um listener de evento personalizado, você precisa:
 Veja um exemplo simples de uma classe de listener de evento personalizado:
 
 ```python
-from crewai.utilities.events import (
+from crewai.events import (
     CrewKickoffStartedEvent,
     CrewKickoffCompletedEvent,
     AgentExecutionCompletedEvent,
 )
-from crewai.utilities.events.base_event_listener import BaseEventListener
+from crewai.events import BaseEventListener
 
 class MeuListenerPersonalizado(BaseEventListener):
     def __init__(self):
@@ -146,7 +146,7 @@ my_project/
 
 ```python
 # my_custom_listener.py
-from crewai.utilities.events.base_event_listener import BaseEventListener
+from crewai.events import BaseEventListener
 # ... importe events ...
 
 class MyCustomListener(BaseEventListener):
@@ -268,7 +268,7 @@ Campos adicionais variam pelo tipo de evento. Por exemplo, `CrewKickoffCompleted
 Para lidar temporariamente com eventos (útil para testes ou operações específicas), você pode usar o context manager `scoped_handlers`:
 
 ```python
-from crewai.utilities.events import crewai_event_bus, CrewKickoffStartedEvent
+from crewai.events import crewai_event_bus, CrewKickoffStartedEvent
 
 with crewai_event_bus.scoped_handlers():
     @crewai_event_bus.on(CrewKickoffStartedEvent)

docs/pt-BR/concepts/knowledge.mdx

@@ -681,11 +681,11 @@ O CrewAI emite eventos durante o processo de recuperação de knowledge que voc
 #### Exemplo: Monitorando Recuperação de Knowledge
 
 ```python
-from crewai.utilities.events import (
+from crewai.events import (
     KnowledgeRetrievalStartedEvent,
     KnowledgeRetrievalCompletedEvent,
+    BaseEventListener,
 )
-from crewai.utilities.events.base_event_listener import BaseEventListener
 
 class KnowledgeMonitorListener(BaseEventListener):
     def setup_listeners(self, crewai_event_bus):

docs/pt-BR/concepts/llms.mdx

@@ -708,10 +708,10 @@ O CrewAI suporta respostas em streaming de LLMs, permitindo que sua aplicação
     O CrewAI emite eventos para cada chunk recebido durante o streaming:
 
     ```python
-    from crewai.utilities.events import (
+    from crewai.events import (
       LLMStreamChunkEvent
     )
-    from crewai.utilities.events.base_event_listener import BaseEventListener
+    from crewai.events import BaseEventListener
 
     class MyCustomListener(BaseEventListener):
         def setup_listeners(self, crewai_event_bus):