Implement builtin chunk method as ingestion pipeline in GO (#16822)

### Summary

Implement builtin chunk mehtod as ingestion pipeline in GO

internal/entity/kb.go

@@ -58,7 +58,6 @@ const (
 	ParserTypeOne          ParserType = "one"
 	ParserTypeAudio        ParserType = "audio"
 	ParserTypeEmail        ParserType = "email"
-	ParserTypeKG           ParserType = "knowledge_graph"
 	ParserTypeTag          ParserType = "tag"
 )
 

internal/entity/models/types.go

@@ -202,6 +202,7 @@ type OCRConfig struct {
 }
 
 type ParseFileConfig struct {
+	ParseMethod string `json:"parse_method"`
 }
 
 // EmbeddingModel wraps a ModelDriver with embedding-specific configuration