This contains to related things:
1. An adapter allowing an hclog interface to take in information and send them to the eventer
2. A gate on the eventer, which is the analogue to the behavior prior to eventing where we'd ensure logs were not printed prior to the startup information. Without this, plugin logs using the hclog adapter will start showing up too early.
* `recovery` is only used by the API (and the main module, for decryption)
* `wrapper` is only used by the CLI right now
Moving these brings them closer to the code that uses them, and makes
the SDK package a bit more clear in terms of functionality.