Improvements to Registration and Synchronization to enable two-way sync in more scenarios

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The goal is to develop a simplified registration process and synchronization protocol.

Considerations

• Open Registration: A device user can register without central administration of the device (like SP1 registration)
• Managed Registration: Projects that want more control over registration can require device registration (like SP2 registration)
• Improved security for "open" registration -- unique token set up per-device during registration
• Two-way Synchronization of Docs in Open Registration

To Investigate

• Will moving sync-protocol selection to the new-group component break anything
• Conflict handling for synching of school, class, student, and teacher records
  - Scenario 1: Info is centrally imported from the server. Teachers prevented from changing info
  - Scenario 2: Teachers are able to create classes and students.
  - Scenario 3: Two teachers share a class -- need to sync data between the two devices

Related:
#3471