improve file operations, update docstrings

[ajinkya-kulkarni]

• Changed the import statement for the Image class from PIL to PIL.Image.
• Updated the image_comparison function to include a docstring.
• Now creates a temporary file path using the os.path.join() function
• Updated the height calculation to convert the result to an integer using the int function.
• Added a in_memory flag to the image_comparison function to handle pillow to base64 conversion in memory without saving to local.
• Simplified the conditional statement in the image_comparison function for checking whether to convert images to base64 strings in memory or from temporary files.
• Updated the pillow_local_file_to_base64 function to accept a directory path as a parameter, so that it can save the temporary file in the specified directory.

[ajinkya-kulkarni]

I checked the code on my end - works fine

[fcakyon]

@ajinkya-kulkarni thank you so much for this awesome contribution!