ErrorReporting: Add API method to add error report from users

The API should allow users to send in error reports.

NOTE: this could technically be a part of some other API, since this is not a core operation in a SMS/LMS. It would probably start as a method here nonetheless, probably something like /api/v1/issues - POST {title:"some title", description:"a more detailed description", base64ScreenshotImage:"an optional Base64 encoded screenshot of the issue"}