addContentWatcher method
Adds a user as a watcher to a piece of content. Choose the user by doing one of the following:
- Specify a user via a query parameter: Use the accountIdto identify the user.
- Do not specify a user: The currently logged-in user will be used.
Note, you must add the X-Atlassian-Token: no-check header when making a
request, as this operation has XSRF protection.
Permissions required: 'Confluence Administrator' global permission if specifying a user, otherwise permission to access the Confluence site ('Can use' global permission).
Implementation
Future<void> addContentWatcher(
    {required String contentId,
    String? key,
    String? username,
    String? accountId}) async {
  await _client.send(
    'post',
    'wiki/rest/api/user/watch/content/{contentId}',
    pathParameters: {
      'contentId': contentId,
    },
    queryParameters: {
      if (key != null) 'key': key,
      if (username != null) 'username': username,
      if (accountId != null) 'accountId': accountId,
    },
  );
}