Feat: add mechanism to check cancellation in Agent (#10766)

### What problem does this PR solve?

Add mechanism to check cancellation in Agent.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

agent/component/message.py

@@ -89,6 +89,9 @@ class Message(ComponentBase):
         all_content = ""
         cache = {}
         for r in re.finditer(self.variable_ref_patt, rand_cnt, flags=re.DOTALL):
+            if self.check_if_canceled("Message streaming"):
+                return
+
             all_content += rand_cnt[s: r.start()]
             yield rand_cnt[s: r.start()]
             s = r.end()
@@ -104,6 +107,9 @@ class Message(ComponentBase):
             if isinstance(v, partial):
                 cnt = ""
                 for t in v():
+                    if self.check_if_canceled("Message streaming"):
+                        return
+
                     all_content += t
                     cnt += t
                     yield t
@@ -111,7 +117,7 @@ class Message(ComponentBase):
                 continue
             elif not isinstance(v, str):
                 try:
-                    v = json.dumps(v, ensure_ascii=False, indent=2)
+                    v = json.dumps(v, ensure_ascii=False)
                 except Exception:
                     v = str(v)
             yield v
@@ -120,6 +126,9 @@ class Message(ComponentBase):
             cache[exp] = v
 
         if s < len(rand_cnt):
+            if self.check_if_canceled("Message streaming"):
+                return
+
             all_content += rand_cnt[s: ]
             yield rand_cnt[s: ]
 
@@ -133,6 +142,9 @@ class Message(ComponentBase):
 
     @timeout(int(os.environ.get("COMPONENT_EXEC_TIMEOUT", 10*60)))
     def _invoke(self, **kwargs):
+        if self.check_if_canceled("Message processing"):
+            return
+
         rand_cnt = random.choice(self._param.content)
         if self._param.stream and not self._is_jinjia2(rand_cnt):
             self.set_output("content", partial(self._stream, rand_cnt))
@@ -145,6 +157,9 @@ class Message(ComponentBase):
         except Exception:
             pass
 
+        if self.check_if_canceled("Message processing"):
+            return
+
         for n, v in kwargs.items():
             content = re.sub(n, v, content)