当后端有告知最佳刷新率时，设置最佳刷新率为推荐刷新率，如没有，则设置为最高刷新率为推荐刷新率

Log: 安装完UOS系统，显示器没有匹配到系统默认推荐的刷新率
Bug: https://pms.uniontech.com/zentao/bug-view-40127.html
Change-Id: I6c6a67714a7b0ea6be39ed71620faeb716ad6a8f
Reviewed-on: http://gerrit.uniontech.com/c/dde-control-center/+/3639
Reviewed-by: <mailman@uniontech.com>
Reviewed-by: wangwei <wangwei@uniontech.com>
Reviewed-by: pengwenhao <pengwenhao@uniontech.com>
Tested-by: <mailman@uniontech.com>