Given an array of strings `strs`, group **the anagrams** together. You can return the answer in **any order**. An Anagram is a word formed by rearranging the letters of a different word, using all the original letters exactly once.
Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"]]
Input: strs = [""]
Output: [[""]]
Input: strs = ["a"]
Output: [["a"]]