Allow a teacher/admin to see the list of lessons with controls

[amellie]

Dependency

Depends on #21 and #16

Story

As a Teacher or an Admin
I Want to see the list of existing lessons
So That I can see review these lessons and perform actions (create/update/etc)

Acceptance Criteria

• The page should only be accessible by a teacher/admin
• The page can be accessed from the module list page created in Allow a teacher/admin to see the list of modules with controls #21. You need to modify the module list page so that the lesson numbers are linked to this page
• The page should contain the module name as well as a table containing these columns:
  -- Name (of the lesson)
  -- Type
  -- Action (which contains: Edit and Delete button)
• A Create button should be added to the top of the table. When the button is clicked, it should show the page that has been done in Allow a teacher or admin to create a new lesson #16
• Edit and Delete buttons do not do anything when clicked (this will be handled in another task, so please leave it as is)