Use a locale switcher cookie based on unified HOT login cookie

[spwoodcock]

• Once global HOT login is working, the users have a preferred language defined.
• Ideally we can just pull from this on first load of FieldTM, saving the user having to set the locale manually.
• Order
  1. Manual language override cookie
  2. HOT profile preferred language
  3. Browser language
  4. English

[linear]

TECH-1075