refactor(functionscalls.py): extract get_final_url function to improve code modularity and reusability
refactor(functionscalls.py): simplify send_a_stock_image function by using get_final_url function and improving message formatting
feat(main.py): add newline at the end of the file for consistency
chore(functionscalls.py): remove extra blank lines
feat(functionscalls.py): add unsplash_random_image_url constant for generating random image URLs
feat(functionscalls.py): add add_reaction_to_last_message() function for adding reactions to the last message
