🐛 fix(GenerationContext.py): fix import statements and add support for captioning engine

✨ feat(GenerationContext.py): add support for captioning engine in the GenerationContext class
The import statement for the `moviepy.editor` module is changed to `moviepy.editor as mp` to improve code readability. Additionally, the `gradio` module is imported as `gr` to improve code readability. The `GenerationContext` class now includes a `captioningengine` parameter and initializes a `captioningengine` attribute. The `setup_dir` method is modified to include a call to create a directory for the output files. The `get_file_path` method is modified to return the file path based on the output directory. The `process` method is modified to include additional steps for captioning. The `timed_script` attribute is added to store the result of the `ttsengine.synthesize` method. The `captioningengine` is used to generate captions and store them in the `captions` attribute. The final video is rendered using the `moviepy` library and saved as "final.mp4" in the output directory.

src/engines/LLMEngine/OpenaiLLMEngine.py

@@ -38,7 +38,7 @@ class OpenaiLLMEngine(BaseLLMEngine):
                 {"role": "system", "content": system_prompt},
                 {"role": "user", "content": chat_prompt},
             ],
-            max_tokens=max_tokens,
+            max_tokens=int(max_tokens) if max_tokens else openai._types.NOT_GIVEN,
             temperature=temperature,
             top_p=top_p,
             frequency_penalty=frequency_penalty,