gui/notes: Authorize OAuth Cozy client
gui/notes: Authorize OAuth Cozy client

  The old OAuth client needs to be authorized before we build a new
  `CozyClient` from it otherwise we don't have any credentials to reuse
  and the final client won't be instanciated.

  This was previously done automatically by the first request made with
  the old client so we didn't have to do it explicitely.

cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop,cozy-labs/cozy-desktop