Fix the following issue:
I want the manimgl and manim-render commands to support opening or revealing rendered output files directly from the CLI. When I run manimgl path/to/scene.py SceneName --open or manimgl path/to/scene.py SceneName -o, the command should render the scene to a media file just like --write_file, and after the movie or final-frame image has been saved it should launch that saved file with the platform's default opener. Passing --open by itself should imply file writing; users should not also have to pass --write_file.
I also want manimgl path/to/scene.py SceneName --finder to imply file writing and then reveal the saved output in the operating system's file browser when rendering completes. If the run saves only the final frame with --skip_animations, the image file should be opened or revealed; otherwise the movie file should be opened or revealed. These flags should appear in manimgl --help with -o, --open described as automatically opening the saved file and --finder described as showing the output file in Finder/file browser. A successful render that opens or reveals the output should still exit with code 0.