Better iconography for secret editing

[raymondberg]

Secrets: the lock symbol makes me think it is toggling the editability of the section -- not whether it is a secret or not
a spy icon -- hat and glasses -- may make the action of the button more clear (source: https://www.flaticon.com/free-icons/spy)
if using "hat and glasses" to indicate "secret" then "X over hat with glasses" or "circle with line over hat with glasses" could indicate "not secret"
if not using "hat with glasses" then "moon" could indicate "secret" and "sun" could indicate "not secret" (source: flaticon has these too)
open and closed eyes could also work