Preferences: Fix 2FA issues by using /me/preferences endpoint

[mcsf]

Requires D5992-code

Fixes #202 #3666
… as well as its numerous related issues.

[matticbot]

Test live: https://calypso.live/?branch=update/calypso-preferences-endpoint

[mcsf]

Rebased

[matticbot]

@mcsf This PR needs a rebase

[lancewillett]

I gave this a spin today (together with sandboxing the API patch) and wasn't able to fully get the new endpoint working. However, testing in the Live Branch I verified the new API call made from to /me/preferences even though it resulted in a 404. :)

[lancewillett]

Using the new API endpoint on the backend now works (patch updated). 👍

Testing with the live branch (and sandboxed API requests) I'm able to see a successful call to the new /me/preferences endpoint from https://calypso.live/me.

GET /rest/v1.1/me/preferences?http_envelope=1 HTTP/1.1
Host: public-api.wordpress.com
URL: https://public-api.wordpress.com/rest/v1.1/me/preferences?http_envelope=1
Status code: 200 OK

[mtias]

Thanks for tackling this one.

[mcsf]

Thanks for looking! Removing Needs Review and adding Hold as we work on the endpoint itself.

[mcsf]

D5992-code has been deployed. This PR has been rebased and retested. Going to merge this. :)

cc @aduth to keep you in the loop, as you've worked on Preferences a lot

[folletto]

YES THANK YOU!!! :D