add UI options for PGP to use or generate an ID

Reference: #671

Aldo for some guidance: https://source.puri.sm/Librem5/debs/pkg-chatty/-/wikis/Hardware-Encrypted-Communication-Setup

To make GPG Key: https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html