input: Write a python function to store and display contact information in a dictionary.
  assert store_and_display_contacts({'John': '1234567890'}) == 'John: 1234567890'
  assert store_and_display_contacts({'Alice': '9876543210', 'Bob': '5555555555'}) == 'Alice: 9876543210\nBob: 5555555555'
  assert store_and_display_contacts({}) == ''
output: def store_and_display_contacts(contacts):
      return '\n'.join([f"{name}: {number}" for name, number in sorted(contacts.items())])