The textarea and orientation select and create button in the Transcriptions modal should be disabled when the user doesn't have write rights on the element

On an element with an image, when opening the transcriptions modal from the element tree, the text area and the create button etc aren't disabled even if you can't create a transcription, you can hit the button and get a "You do not have write rights" error notification. It would make more sense for all this to be disabled when the user doesn't have Write rights.