use conditional imports and show help errors if modules not found

src/dailyai/pipeline/frames.py

@@ -1,9 +1,6 @@
 from dataclasses import dataclass
 from typing import Any, List
 
-from dailyai.services.openai_llm_context import OpenAILLMContext
-import dailyai.pipeline.protobufs.frames_pb2 as frame_protos
-
 
 class Frame:
     def __str__(self):
@@ -135,14 +132,6 @@ class LLMMessagesFrame(Frame):
     messages: List[dict]
 
 
-@dataclass()
-class OpenAILLMContextFrame(Frame):
-    """Like an LLMMessagesFrame, but with extra context specific to the
-    OpenAI API. The context in this message is also mutable, and will be
-    changed by the OpenAIContextAggregator frame processor."""
-    context: OpenAILLMContext
-
-
 @dataclass()
 class ReceivedAppMessageFrame(Frame):
     message: Any