CLC-4321 - Investigate possible issues with pending eGrades Export tool

https://jira.ets.berkeley.edu/jira/browse/CLC-4321

Provides validation and appropriate error display when state of course site not appropriate for eGrade Export. Ensures that export uses letter grade provided by Canvas via Grading standard/schemes, and only includes student grades from selected section.
Truthfully Christian, I just did this to that one method, so that the symbols are camelcased, but it just makes me feel like I'm introducing an inconsistent convention. I totally have no problem assigning values from underscore keys to camelCase variables within the Javascript. It doesn't seem like the camelcase in JSON issue is resolved yet though.

Maybe I can come up with a simple function that does, recursively even, and then we can start doing this as much as possible