feat/enhance the multi-modal support (#8818)

api/core/variables/segment_group.py

@@ -0,0 +1,22 @@
+from .segments import Segment
+from .types import SegmentType
+
+
+class SegmentGroup(Segment):
+    value_type: SegmentType = SegmentType.GROUP
+    value: list[Segment]
+
+    @property
+    def text(self):
+        return "".join([segment.text for segment in self.value])
+
+    @property
+    def log(self):
+        return "".join([segment.log for segment in self.value])
+
+    @property
+    def markdown(self):
+        return "".join([segment.markdown for segment in self.value])
+
+    def to_object(self):
+        return [segment.to_object() for segment in self.value]