New i18n strings for release

Feature branch: ORA staff grading

ORA staff grading translation updates

Editor Assessments Order improvements

Now setting self.editor_assessments_order whenever we correct it for
template rendering, and modifying the logic to be more careful with
how assessments types not-specified-by-the-user are presented so
that they remain in the default, legal order.

Improve text strings

Changing wording of "waiting for peers" message.

Be robust to username not being available.

TNL-4019

TNL-4018

TNL-4027

These are the strings that were pulled from our source, pushed to
Transifex, and need to be pulled back down before merging all of
the staff grading work later this week.

Render Incomplete simplification

Simplfying logic for display strings in all "user action needed" states.

Fixing up oa_response

With staff now being a possibility, we need to update oa_response_complete.
Now keeping "Needs to be graded" and "You need to do things" separate. Includes
test fixes.

Staff can view uploaded files

Emulating the approach used by peer_mixin to allow staff to actually
see uploaded files. Also updates oa_student_info to make use of
oa_uploaded_file.html instead of duplicating that logic. Test
updates also included.

i18n fixes

Properly translate strings *before* passing as variable

Move focus within staff panels.

TNL-3932

Make checkboxes accessible.

TNL-3999

The crux of this fix is that scored_only behavior in various api/peer.py
methods is no longer needed, or correct. This value has been removed, so
that assessments may be gotten (and medians found) when the assessments
are not used in determining the final score (say, if a staff score exists).

Also includes updates to the "waiting for steps" string as prescribed by
@catong in https://github.com/edx/edx-ora2/pull/764, along with logic for
that method, and updates to tests and get_wating_details logic in light
of this simplification.

TNL-3958

The refresh model in the staff grading form changed.
Also add a "scrollToTop" call when continuing grading.

TNL-3870

Full staff grading UI

Includes fixing my previous work on the staff assessment test to
use the required flow, not the override. Also refactors full workflow
tests and adds a new one to include a required staff grading step.