Build educator account creation & classroom code infrastructure

[patudom]

• Implement OAuth logon for educator
• Associate OAuth generated user ID with a new educator ID in db
• Build pages where educators enter in their courses to generate a classroom code

[patudom]

Updated schematic is here. @johnarban and @Carifio24, please review the schematic to check if the flow would make sense to an educator and if it includes all the relevant backend links we will need to sync everything up. If you think we're in a good enough starting place, please work with @nmearl to set up these pages in Solara.

(You will need to be logged on to team google drive to access the linked google slideshow).