Use `help` instead of `to_s` to represent the schema's help text

The previous method for storing help was in the object's default serialized
representation. Much more appropriate, used here, is a different method
called `help`.

For https://tickets.puppetlabs.com/browse/RAZOR-272
Add CLI example capability

In order to support examples that are customized for the command line client
interface, we need to build out a more robust format for the help texts
stored on the server. The help for each command now includes several pieces:
- "full" is still present to support older clients
- "summary"/"description"/"returns"/"examples"/"schema" added for each
component
- "examples" is a nested object: "api" and/or "cli" can be present

Clients (namely the CLI) should display these attributes if present in the
help text's JSON.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-272
Translate API help examples into CLI help examples

The help examples that currently exist are only for direct API calls, or for
sending a JSON file for a command. This change translates the existing
examples into a CLI format, which will be available alongside the existing
API examples.

Fixes https://tickets.puppetlabs.com/browse/RAZOR-272