[featurePR]使FlutterBoost支持iOS系统导航栏是否隐藏功能

**问题描述：**
NativeA跳到FlutterB的时候，由于iOS的Controller是共享了NavigationBar，FlutterB也会被加上NativeA的导航栏。

**解决思路：**
1、FlutterBoostRouteOptions添加navigationBarHidden参数
2、FBFlutterViewContainer在viewWillAppear中根据参数设置self.navigationController的navigationBarHidden

Locate FlutterBoostRouteOptions and FBFlutterViewContainer, then read how route options reach the container and how viewWillAppear is handled. Add the navigation-bar visibility option and verify that the container applies it when the Flutter route appears, including the shared iOS navigation bar behavior.

Written by the indexing model from the issue text.