Add-ons [MMO] Title Warning 2.3.1

Fix URL detection in title warning by using regex pattern matching

• Replace word-splitting approach with regex-based matching:
  Phrases with special chars (URLs, etc.) match as substrings
• Regular words match with word boundaries (\b)

• Support XF2.3
• Min require XF2.3
• Fixed extension
• Now if a word contains a forbidden word, it is checked because it can only be a part, perhaps in the future there will be support for lemmas
• Using string helpers from XF