PDF functionality is now read-only. Auto generating pdf's
function to be craeted.

`vet_submitted_reports` is updated such that the amount of logic is
reduced and 1/2 view is dropped.
`submit_report` has extra precheck before submitting report, checking
if submission is open for reporting. Else, only submit report
if user has invitation.

Needed refactoring of submit manuscript flow.
Checks are run via the forms. Also, the copying
of data from old submissions is done via forms.

All this functionality is removed from the model.

Need to rerun `add_groups_and_permissions` command.

and browse) to a Class Based View, using
the ListView class as a base.
Also adds in the permission checks in the
submission process, both in the
PrefillUsingIdentifier as in the
SubmissionCreateView. This should prevent
any unauthorized submissions.