chore: Add missing matrix error types as per spec

The full list of error codes is here:
https://spec.matrix.org/v1.1/client-server-api/#standard-error-response

lib/src/model/matrix_exception.dart

@@ -1,17 +1,17 @@
 /* MIT License
-* 
+*
 * Copyright (C) 2019, 2020, 2021 Famedly GmbH
-* 
+*
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
-* 
+*
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
-* 
+*
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@@ -40,6 +40,23 @@ enum MatrixError {
   M_MISSING_PARAM,
   M_UNSUPPORTED_ROOM_VERSION,
   M_UNRECOGNIZED,
+  M_BAD_JSON,
+  M_NOT_JSON,
+  M_UNAUTHORIZED,
+  M_USER_DEACTIVATED,
+  M_INVALID_USERNAME,
+  M_ROOM_IN_USE,
+  M_INVALID_ROOM_STATE,
+  M_SERVER_NOT_TRUSTED,
+  M_INCOMPATIBLE_ROOM_VERSION,
+  M_BAD_STATE,
+  M_GUEST_ACCESS_FORBIDDEN,
+  M_CAPTCHA_NEEDED,
+  M_CAPTCHA_INVALID,
+  M_INVALID_PARAM,
+  M_EXCLUSIVE,
+  M_RESOURCE_LIMIT_EXCEEDED,
+  M_CANNOT_LEAVE_SERVER_NOTICE_ROOM,
 }
 
 /// Represents a special response from the Homeserver for errors.