Add basic support for OAuth 2.0 Device Authorization Grant in oauth2-core, including:
- Parameter names in
OAuth2ParameterNames - Classes for device code and user code that extend
AbstractOAuth2Token HttpMessageConverterfor Device Authorization Response- New
AuthorizationGrantTypeconstant forurn:ietf:params:oauth:grant-type:device_code
Issue spring-projects/spring-authorization-server#44