text: Title: [DOC] Add type hints for similarity search
  Body: ### Describe the feature or idea you want to propose
  
  Other modules are increasingly using type hints in the function declaration, the similarity search module should do the same.
  
  ### Describe your proposed solution
  
  Implement type hint in function declaration similarly to as it's done in other modules.
  
  ### Describe alternatives you've considered, if relevant
  
  _No response_
  
  ### Additional context
  
  _No response_