Split String by Identical Characters

Create a function that splits a string into an array of identical clusters.

Examples

split_groups("555") ➞ ["555"]

split_groups("5556667788") ➞ ["555", "666", "77", "88"]

split_groups("aaabbbaabbab") ➞ ["aaa", "bbb", "aa", "bb", "a", "b"]

split_groups("abbbcc88999&&!!!_") ➞ ["a", "bbb", "cc", "88", "999", "&&", "!!!", "_"]

Notes

• Each cluster should only have one unique character.
• The resulting array should be in the same order as the input string.
• Should work with letters, numbers and other characters.