Assignment submission support in the Mobile app

Assignment submission support in the Mobile app
Project state	In Progress
Tracker issue	https://tracker.moodle.org/browse/MOBILE-1396
Discussion	https://moodle.org/mod/forum/view.php?id=7798
Assignee	{{{assignee}}}

Moodle Web Services

Existing Web Services that will be used:

• mod_assign_get_assignments: To list all the assignments in a course (and retrieve information for a particular assignment)
• mod_assign_save_submission: To save a user submission (including online text and files referenced via draftid)
• mod_assign_submit_for_grading: In case the assignment is configured to display a Submit button, this WS will be used for processing the submission.
• webservice/upload.php endpoint - To submit files and get a draftid

New Web Services required:

mod_assign_get_submission_status

For retrieving all the submission required information (grading summary, current attempt status, feedback data and the attempts history. See MDL-52924

mod_assign_view_submission_status

For triggering the submission viewed event. See MDL-52974