Pre App Demo Improvements

Several adjustments and improvements to the API before demo with Global DS
 - pages are now named and referenced by their ID, not the hash of the content.  this will allow mobile apps to request a specific page by its ID for easier refreshing during translation
 - adding an endpoint to `DraftResource` to fetch just one page of a draft translation
 - improve and correct logic to determine if a package has been uploaded to translation tool
 - enforce only one draft per translations (package & language combo)
 - minor bug while creating a new translation.. translated text was being lost