App update

Submodule web/app 0d35739..7914fa8:
  > Add the general pattern on the mark search page
  > CSS refactoring
  > Add the button to add the currently displayed mark to the working folder
  > Add the "exercises_folder" table
  > Rename the Close button on the mark search page
  > Close the exercise rename dialog on outside click
  > Change the routes for the exercises and mark search
  > Add the 'Exercises' link to the admin navigation
  > Move the jinja variable 'admin' to the my_template_render() function
  > Refactor the pfsp friendly name generation in the trainer search function