Fix error handling for http errors everywhere

[px-amaac]

• This commit adds check for response codes >= 400 on registration request and service configuration request and brings token request to use the same format
• Creates TYPE_HTTP_ERROR(5) in AuthorizationException
• Add method to create AuthorizationException of HTTP_ERROR type from http response code and message. Using HttpURLConnection.getErrorStream() to fill out errorDescription.
• Add tests for each area changed to handle a bad request http error.

This PR follows in line with what was done for openid#144 following Android documentation and Recommendations from Oracle on handling http error responses here. The change in openid#144 did not address this issue in other places of the library and could potentially throw json exception if error stream does not contain a valid JSON response.