TAs metagrading PDF submissions see the score as 0.00/###

[blerner]

When a TA metagrades a submission containing a PDF, with comments, they don't see a correctly computed score:

This is because the code at the end of _enter_comments.js.erb is asynchronous and runs in the wrong order:

• It iterates over all the PDF page containers and starts to create PDF viewers for them, then
• Calls updateScore before the viewers are ready, then
• the viewers get ready, and insert page comments, but don't call updateScore again.

https://github.com/CodeGrade/bottlenose/blob/352c4321bf22bd68bc897379744c51e3fadf4f89/app/views/grades/_enter_comments.js.erb#L387-L414

The fix is to add a call to updateScore at the end of loadPageComments (https://github.com/CodeGrade/bottlenose/blob/352c4321bf22bd68bc897379744c51e3fadf4f89/app/views/grades/_enter_comments.js.erb#L310-L349), to ensure that whenever the comments do get loaded, the score gets recomputed.