Implement of "Protected Headers for Cryptographic E-mail". T742
Summary:
Currently protected headers are in draft status for an RFC:
https://datatracker.ietf.org/doc/draft-autocrypt-lamps-protected-headers/
Test Plan: run autotests successfully
Subscribers: kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D28448