These routes are public: no authentication is required for them.
Returns an image chosen by the user as their avatar. If no image has been
chosen, a fallback will be used, depending of the
fallback parameter in the
default: a default image that shows the Cozy Cloud logo, but it can be overriden by dynamic assets per context
initials: a generated image with the initials of the owner’s public name
404: just a 404 - Not found error.