Create a new BLOB Type. 
- Resource Management:
 - This function allocates resources that must later be freed by calling DOFType_Destroy.
 
If the minSize and maxSize are the same, a fixed-size BLOB type is created. Otherwise, a variable-size BLOB is created.
- Parameters
 - 
  
    | minLength | The minimum size of this type, in bytes. This should be less than maxLength.  | 
    | maxLength | The maximum size of this type, in bytes. This should be greater than minLength. | 
  
   
- Returns
 - The new DOFType, or NULL if it could not be created.