This should speed up some of the jobs, as they will not have to install
node and npm anymore.

There is no particular reason we should should use password strings as
secrets because our underlying cryptographic implementation works just
as well with any kind of bytes.

This adds support for encryption formats that can be encrypted and
decrypted in the browser and on the server side.

Our first iteration uses AES-GCM for encryption with PBKDF2+SHA-256 for
key derivation.