- rake locomotive:upgrade:rename_collections

- locales updates (en / fr)

  - theme_assets.images => theme_assets.image_picker
  - assets => content_assets
  - EditableXXX => Locomotive::EditableXXX (in mongodb)
  - content_types:
    - category => select
    - highlighted_field_name => highlighted_field_id
    - api_enabled => public_form_enabled
    - api_accounts => public_form_accounts