Module navigation changes

[esmeetewinkel]

• Module completion progress on home screen #149
• Module completion progress bar on module_landing is "out of articles"
• Module completion progress bar in sequence is "out of articles"
• Want back button within the module to navigate back to the previously visited page, rather than the first page of the previous category.
• No module overview page (with all categories) until module has been completed. This resolves the issues with navigating to an uncompleted category by pressing back, and launching the congratulations pop-up on completing the last category of the module.
• Module overview page does appear when revisiting a completed module.

[esmeetewinkel]

Break out remaining point into separate issue, closing here