Given an array of strings strs, group the anagrams together. You can return the groups in any order, and the strings within a group can be in any order.
Two strings are anagrams if one can be rearranged into the other using all the original letters exactly once.
Example
Input: strs = ["eat", "tea", "tan", "ate", "nat", "bat"]
Output: [["bat"], ["nat", "tan"], ["ate", "eat", "tea"]]