🐛 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/NoneEngine.py

@@ -0,0 +1,14 @@
+from . import BaseEngine
+
+
+class NoneEngine(BaseEngine):
+    num_options = 0
+    name = "None"
+    description = "No engine selected"
+
+    def __init__(self):
+        pass
+
+    @classmethod
+    def get_options(cls):
+        return []