Log API Requests

With the creation of the API #273 and our goal of making it _easy_ for _anyone_ to request their @dwyl App data via JSON/WebSockets, we need to have the means of _logging_ requests in place quite soon ... 💭 ⏳

# Story

As a `developer` building an App with an API,
I want to have logging of all API requests
So that we can detect anomalous usage patterns and guarantee service levels.

> **Note**: by having API request logging we will _automatically_ have UI request logging because we are using [Content Negotiation](https://github.com/dwyl/phoenix-content-negotiation-tutorial/issues/1) to render JSON for API and HTML for UI requests to the _same_ route.
> This issue is _specific_ to API Logging because it's the highest "risk" for abuse and potential data breach. If someone accidentally leaks their `AUTH_API_KEY` e.g. by committing some code to GitHub, they could leak all their data. We need to avoid that by having logging to prevent new devices from accessing data. i.e. we need to log the device ID + IP address of all API requests so that we can check if **`new`** devices/IPs are being used and force a re-auth.

# Todo

+ [ ] Create a `logs` Schema/Table (_for MVP we will store the logs in the same DB, we can split them out into a separate service later or use a 3rd Party Service like Timber.io, Logstash, [etc.](https://stackshare.io/timber-io/alternatives)
+ [ ] `email` - encrypted email of the person the login attempt was made for. This allows us to keep track of how many attempts were made for a given account in a set time frame. If not set, leave `null`
+ [ ] `person_id` - if the request is authenticated, log the `person_id` otherwise just the `email` so that we can later analyse the _failed_ login attempts. (e.g: typos)
+ [ ] `apikey_id` - the `AUTH_API_KEY` used for the request.
+ [ ] `ip_address` - so we can rate limit by `person_id` and `ip_address` and so that we can inform people when their account has been accessed from an unrecognised IP.
see: https://github.com/dwyl/hits/blob/cd9a8e15c6e598281b7bc6b037963dab6ac515f8/lib/hits_web/controllers/hit_controller.ex#L32-L33
+ [ ] `user_agent_id` - same as in Hits, we will have a `user_agents` schema where we store the full User Agent string then we reference it in the log rather than duplicating it.
See: https://github.com/dwyl/hits/blob/cd9a8e15c6e598281b7bc6b037963dab6ac515f8/lib/hits.ex#L48-L58
> This will eventually be replaced by "Client Hints" for better privacy (_according to Google_) 🙄
see: https://www.zdnet.com/article/google-to-phase-out-user-agent-strings-in-chrome )
> Probably not for the next year. So for now, User Agent Strings. 👍
+ [ ] `timstamps` (_default in all Ecto/Phoenix schemas_)

This is related to: Logging "Login" Attempts: https://github.com/dwyl/auth/issues/67 (`P2`)
and Logging in General: https://github.com/dwyl/learn-devops/issues/60