Insert and Search Words with Wildcards

Design and implement a data structure that supports the following operations:

• insert(word: str) -> None: Inserts a word into the data structure.
• search(word: str) -> bool: Returns true if a word exists in the data structure and false if not. The word may contain wildcards ('.') that can represent any letter.

Example:

Input: [
  insert('band'),
  insert('rat'),
  search('ra.'),
  search('b..'),
  insert('ran'),
  search('.an')
]
Output: [True, False, True]

Explanation:

insert("band") # data structure has: "band"
insert("rat")   # data structure has: "band" and "rat"
search("ra.")   # "ra." matches "rat": return True
search("b..")   # no three-letter word starting with ‘b' in the
               # data structure: return False
insert("ran")  # data structure has: "band", "rat", and "ran"
search(".an")  # ".an" matches "ran": return True

Constraints:

• Words will only contain lowercase English letters and '.' characters.