transport(output): emit new bot start|stop speaking frames

src/pipecat/frames/frames.py

@@ -270,17 +270,6 @@ class BotInterruptionFrame(SystemFrame):
     pass
 
 
-@dataclass
-class BotSpeakingFrame(SystemFrame):
-    """Emitted by transport outputs while the bot is still speaking. This can be
-    used, for example, to detect when a user is idle. That is, while the bot is
-    speaking we don't want to trigger any user idle timeout since the user might
-    be listening.
-
-    """
-    pass
-
-
 @dataclass
 class MetricsFrame(SystemFrame):
     """Emitted by processor that can compute metrics like latencies.
@@ -348,6 +337,33 @@ class UserStoppedSpeakingFrame(ControlFrame):
     pass
 
 
+@dataclass
+class BotStartedSpeakingFrame(ControlFrame):
+    """Emitted upstream by transport outputs to indicate the bot started speaking.
+
+    """
+    pass
+
+
+@dataclass
+class BotStoppedSpeakingFrame(ControlFrame):
+    """Emitted upstream by transport outputs to indicate the bot stopped speaking.
+
+    """
+    pass
+
+
+@dataclass
+class BotSpeakingFrame(ControlFrame):
+    """Emitted upstream by transport outputs while the bot is still
+    speaking. This can be used, for example, to detect when a user is idle. That
+    is, while the bot is speaking we don't want to trigger any user idle timeout
+    since the user might be listening.
+
+    """
+    pass
+
+
 @dataclass
 class TTSStartedFrame(ControlFrame):
     """Used to indicate the beginning of a TTS response. Following