Feat: conversation variable & variable assigner node (#7222)

Signed-off-by: -LAN- <laipz8200@outlook.com>
Co-authored-by: Joel <iamjoel007@gmail.com>
Co-authored-by: -LAN- <laipz8200@outlook.com>

api/core/app/segments/segments.py

@@ -1,4 +1,5 @@
 import json
+import sys
 from collections.abc import Mapping, Sequence
 from typing import Any
 
@@ -37,6 +38,10 @@ class Segment(BaseModel):
     def markdown(self) -> str:
         return str(self.value)
 
+    @property
+    def size(self) -> int:
+        return sys.getsizeof(self.value)
+
     def to_object(self) -> Any:
         return self.value
 
@@ -105,28 +110,25 @@ class ArraySegment(Segment):
     def markdown(self) -> str:
         return '\n'.join(['- ' + item.markdown for item in self.value])
 
-    def to_object(self):
-        return [v.to_object() for v in self.value]
-
 
 class ArrayAnySegment(ArraySegment):
     value_type: SegmentType = SegmentType.ARRAY_ANY
-    value: Sequence[Segment]
+    value: Sequence[Any]
 
 
 class ArrayStringSegment(ArraySegment):
     value_type: SegmentType = SegmentType.ARRAY_STRING
-    value: Sequence[StringSegment]
+    value: Sequence[str]
 
 
 class ArrayNumberSegment(ArraySegment):
     value_type: SegmentType = SegmentType.ARRAY_NUMBER
-    value: Sequence[FloatSegment | IntegerSegment]
+    value: Sequence[float | int]
 
 
 class ArrayObjectSegment(ArraySegment):
     value_type: SegmentType = SegmentType.ARRAY_OBJECT
-    value: Sequence[ObjectSegment]
+    value: Sequence[Mapping[str, Any]]
 
 
 class ArrayFileSegment(ArraySegment):