Add re-generation of encryption key

[SeDemal]

          The key is generated initally, my plan is to add a cli option that allows you to genrate a new key and also update all existing integration secrets

Originally posted by @Meierschlumpf in #1202 (comment)

If this key is shown somewhere in the management page, I also suggest to add a regeneration button there using that same function.

[Meierschlumpf]

It is not shown at any point. IMO it's best to only put it in the CLI and never show it to the user. He can obviously go and take a look at it, but we don't want to have users that don't have so much technical knowledge to have this key shown

[Meierschlumpf]

This is no longer needed as it's now an env variable #1202