Hashmaps are a powerful data structure that allow you to store key-value pairs. In Rust, the HashMap type is provided that uses the a hashing algorithm called SipHash to store keys and values in a way that allows for fast and secure lookups. Think of them as a dictionary in Python or an object in JavaScript.

In this challenge, we want to build a sanctuary registry that allows us to manage animals in different sections of the sanctuary. We'll use a HashMap to store the sections as keys and a Vec to store the animals in each section. Each key is a section name String and each value is a list of animals in that section Vec<String>.

You are given a type of Collection which is a HashMap<String, Vec<String>>. The key is the section name and the value is a list of animals in that section.

Your task is to implement the following functions:

1. add_animal_to_section: This function should add an animal to a section in the registry. If the section does not exist, it should be created. If the animal is already in the section, it should not be added again.

2. get_animals_in_section: This function should return a list of animals sorted alphabetically in a given section. If the section does not exist, it should return an empty list.

3. get_all_animals_sorted: This function should return a copy of the entire registry with all animals sorted alphabetically in each section.

let mut registry = Collection::new();
 
add_animal_to_section("Eagle", "Birds", &mut registry);
assert_eq!(get_animals_in_section("Birds", &registry), vec!["Eagle"]);

• Use the insert method on a HashMap to add a new section or update an existing section.
• Use the entry method on a HashMap to get a mutable reference to a section.
• Use the iter method on a HashMap to iterate over the key-value pairs.
• Use the sort method on a Vec to sort the animals alphabetically.