feat(server): Option to configure SMTPS transport (#22833)

* feat(server): Option to configure SMTPS transport

This commit adds a boolean option in the SMTP transport configuration to
enable the so-called "secure" mode. What it does is use SMTP over TLS
instead of relying on the more common STARTTLS option over plain SMTP.

* Add missing field in dto

* Add missing field

* Use a switch instead of text field

* Add field in spec

* chore: regen open-api

---------

Co-authored-by: Jason Rasmussen <jason@rasm.me>

server/src/services/notification.service.spec.ts

@@ -40,6 +40,7 @@ const configs = {
           ignoreCert: false,
           host: 'localhost',
           port: 587,
+          secure: false,
           username: 'test',
           password: 'test',
         },