refactor: move structured output support outside LLM Node (#21565)

Co-authored-by: Novice <novice12185727@gmail.com>

api/core/model_runtime/entities/llm_entities.py

@@ -1,7 +1,7 @@
-from collections.abc import Sequence
+from collections.abc import Mapping, Sequence
 from decimal import Decimal
 from enum import StrEnum
-from typing import Optional
+from typing import Any, Optional
 
 from pydantic import BaseModel, Field
 
@@ -101,6 +101,20 @@ class LLMResult(BaseModel):
     system_fingerprint: Optional[str] = None
 
 
+class LLMStructuredOutput(BaseModel):
+    """
+    Model class for llm structured output.
+    """
+
+    structured_output: Optional[Mapping[str, Any]] = None
+
+
+class LLMResultWithStructuredOutput(LLMResult, LLMStructuredOutput):
+    """
+    Model class for llm result with structured output.
+    """
+
+
 class LLMResultChunkDelta(BaseModel):
     """
     Model class for llm result chunk delta.
@@ -123,6 +137,12 @@ class LLMResultChunk(BaseModel):
     delta: LLMResultChunkDelta
 
 
+class LLMResultChunkWithStructuredOutput(LLMResultChunk, LLMStructuredOutput):
+    """
+    Model class for llm result chunk with structured output.
+    """
+
+
 class NumTokensResult(PriceInfo):
     """
     Model class for number of tokens result.