CLC-3002 Get academic terms from DB rather than sakai_proxy settings

https://jira.ets.berkeley.edu/jira/browse/CLC-3002

This eliminates the Settings.sakai_proxy terms. Follow-up PRs will eliminate the Canvas and FinAid term configurations.

My first PR failed in Bamboo-testext because certain basic OEC tests weren't being run as part of the normal unit test environment. The second commit fixes that.