Implement LDevID issuing logic

[iadgovuser59]

The goal of this task will be to implement the logic to issue an LDevID certificate for the DevID class created in an earlier task. Broadly speaking, this will involve the following steps:

1. Work with a CA trust chain, loaded from the ACA, to generate an LDevID certificate based off device fields.
2. Sign the generated certificate using a private key (see privateKey() method in the ACA).