Improve ApiDoctor beta error messages to be more actionable

[MIchaelMainer]

@millicentachieng

Needs better actionable error messages - the issue on the lead up to Ignite could have been fixed much earlier if the logs had better error messages. The issue was because of duplicate example ids but the error message didn't make that clear.

@Lauragra @angelgolfer-ms

If you find more issues with unclear ApiDoctor messages, please use this issue thread to capture that information. At some point this should reach a critical mass that we can fix these issues in one swoop.

[angelgolfer-ms]

@MIchaelMainer , @millicentachieng , I think it would be helpful for authors if API Doctor can allow examples in the same topic to refer to the same resource ID (in the SampleKeys attribute preceding the example request). There are scenarios where we would like to be able to show a series of examples in the same topic, referring to the same resource in the example requests.