feat(http): add oauth2 refresh token client

packages/wyatt_http_client/lib/src/utils/authentication_methods.dart

@@ -14,18 +14,8 @@
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
-enum AuthenticationMethods {
-  basic('Basic'),
-  bearer('Bearer'),
-  digest('Digest'),
-  apiKey('ApiKey');
-
-  final String name;
-
-  @override
-  String toString() {
-    return name;
-  }
-
-  const AuthenticationMethods(this.name);
+abstract class AuthenticationMethods {
+  static const String basic = 'Basic';
+  static const String bearer = 'Bearer';
+  static const String digest = 'Digest';
 }