text: Title: Support unicode categories in regex translation checks
  Body: ### Describe the problem
  
  I need to be able to force tighter constraints on some strings across languages that done use a strict a-z.
  Specifically I want to restrict a string down to any letter, number, -, _, and 1-32 in length.
  There's a shorthand regex that works for this:
  ```regex
  ^[-_\p{L}\p{N}\p{sc=Deva}\p{sc=Thai}]{1,32}$
  ```
  This works using python regex (not re), but can't seem to be used with the existing translation flags (tested on webalte 5.9.2).
  
  ### Describe the solution you would like
  
  I would like to be able to apply the following translation flag
  ```regex
  regex:'^[-_\p{L}\p{N}\p{sc=Deva}\p{sc=Thai}]{1,32}$'
  ```
  
  ### Describe alternatives you have considered
  
  DYI checks and rejecting invalid strings when we load the translation
  
  ### Screenshots
  
  ![Image](https://github.com/user-attachments/assets/31e14a3b-370c-424e-bc6f-2508486088aa)
  
  ### Additional context
  
  _No response_