feat: add AgentEvaluator class

This class will evaluate Agent' results and report to user

src/crewai/evaluation/__init__.py

@@ -0,0 +1,39 @@
+# First, import the core base classes without AgentEvaluator
+from crewai.evaluation.base_evaluator import (
+    BaseEvaluator,
+    EvaluationScore,
+    MetricCategory,
+    AgentEvaluationResult
+)
+
+# Now import the evaluators which depend on base classes
+from crewai.evaluation.metrics.semantic_quality_metrics import (
+    SemanticQualityEvaluator
+)
+
+from crewai.evaluation.metrics.goal_metrics import (
+    GoalAlignmentEvaluator
+)
+
+from crewai.evaluation.metrics.reasoning_metrics import (
+    ReasoningEfficiencyEvaluator
+)
+
+
+from crewai.evaluation.metrics.tools_metrics import (
+    ToolSelectionEvaluator,
+    ParameterExtractionEvaluator,
+    ToolInvocationEvaluator
+)
+
+# Next import integration which uses the base classes but not AgentEvaluator
+from crewai.evaluation.evaluation_listener import (
+    EvaluationTraceCallback,
+    create_evaluation_callbacks
+)
+
+
+from crewai.evaluation.agent_evaluator import (
+    AgentEvaluator,
+    create_default_evaluator
+)