Support for CrewAI Observability

[virtualzx-nad]

Original issue: traceloop#2339

Problem:
CrewAI is a framework for orchestrating role-playing autonomous AI agents. We need to add observability support for CrewAI to track and monitor agent interactions and performance.

Requirements:

1. Implement CrewAI instrumentation
2. Track agent interactions and role assignments
3. Monitor task execution and completion
4. Capture agent messages and decisions
5. Add appropriate metrics and spans
6. Include tests and documentation

Difficulty: Moderate
Type: Feature