Editor authentication with OAuth2_Proxy

[Yshayy]

We currently have a mechanism based on node.js passport integrated with the editor for authentication against 3rd party providers (https://github.com/Soluto/tweek/blob/master/services/editor/server/auth/providerSelector.js)
, perhaps we can replace this logic with https://github.com/bitly/oauth2_proxy, and get more providers and UI, additionally, the server binary is only several MB so we can embed it in our image and it doesn't require creating additional service.
The editor itself can read "X-Forwarded-User" and "X-Forwarded-Email" headers for the editor itself.