Added a Apprise URL Details Endpoint (/details)

[caronc]

Description:

Related issue (if applicable): refs #99

Just a nice presentation that can be used to acquire the URLs loaded by Apprise and a quick reference guide to them.

The new URL is /details added to the API.

If you make a request to this same URL and set the Accept Header of application/json, you will get a parse-able JSON response that you can use in your own application.

You can also append ?all=yes to the URL to show all of the services available to you (not just the enabled ones).

The CI is completely broken right now; that's another task for another day. But I wrote all of the test cases for 100% test coverage. So we're good here.

Checklist

• [x] The code change is tested and works locally.
• [x] There is no commented out code in this PR.
• [x] No lint errors (use flake8)
• [x] Tests added

[dokime7]

Wouah I just tested it, it's amazing! Exactly what I need, many thanks!!