use conditional imports and show help errors if modules not found

src/dailyai/pipeline/openai_frames.py

@@ -0,0 +1,12 @@
+from dataclasses import dataclass
+
+from dailyai.pipeline.frames import Frame
+from dailyai.services.openai_llm_context import OpenAILLMContext
+
+
+@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