Write a Python function, called summarize$\_$letters, that receives a string as its

input and returns

a$.$ a list of tuples containing the unique letters in the string and their frequencies.

b$.$ a dictionary where the keys are the unique letters in the string and the values are their

frequencies.

Test your function and display each letter with its frequency. The function should ignore case

sensitivity $($that is$,$a$$ and $$A$$ are the same$)$ and ignore spaces and punctuation. When done,

write a statement that says whether the string has all letters of the alphabet, which can be

determined using set operations. If the string does not have all letters of the alphabet, specify

which letters are missing from it