Encrypt device info on auth flows

[cmonfortep]

Task/Issue URL: https://app.asana.com/0/1201493110486074/1203835825731590/f

Description

Encrypts device info (name and type) on all auth flows.
Also changes QR format to follow b64 encoding

Steps to test this PR

(you will need 2 devices to test some of the auth flows)

create account and login

• install app on device A and device B
• device A(unauthenticated): go to settings -> sync -> create account
• device A(authenticated): show QR code
• device B(unauthenticated): go to settings -> sync
• device B: read QR code
• device B: scan QR code from device A
• device B(authenticated): ensure login success

connect (device B should have a camera)

• install app on device A and device B (both need to be unauthenticated, go to settings -> sync -> reset button)
• device A(unauthenticated): go to settings -> sync
• device A: click on "connect (show QR)" (it will start polling data)
• device B(unauthenticated, with camera!): go to settings -> sync
• device B: click on "connect (read QR)"
• device B: scan QR code from device A
• device B(authenticated): ensure an account is created (account data will appear at the top)
• device A: ensure it joins the same account (can take 7 seconds) (account data will appear at the top)

[cmonfortep]

Current dependencies on/for this PR:

• develop
  • PR Encrypt device info on auth flows #2948 👈

This comment was auto-generated by Graphite.

[cmonfortep]

this was duplicated (probably from a previous merge)

[CDRussell]

nit: maybe move outside of this function for reuse