get_caret_position
Description:
Retrieves the position of the caret inside the accessible object.
Parameters:
| this | 
           the accessible object  | 
      
Returns:
| 
           the position of the caret, in characters  | 
      
Retrieves the position of the caret inside the accessible object.
| this | 
           the accessible object  | 
      
| 
           the position of the caret, in characters  |