IOS 15设置UISearchBar 未编辑居中，编辑居左

原理很简单， 不编辑的时候设置偏移量居中，编辑的时候置0

 [searchBar.searchTextField addTarget:self action:@selector(BeginEdit:) forControlEvents:UIControlEventEditingDidBegin];

        [searchBar.searchTextField addTarget:self action:@selector(EndEdit:) forControlEvents:UIControlEventEditingDidEnd];

-(void)BeginEdit:(UITextField*)textfiled{

    [UIView animateWithDuration:1 animations:^{

        [self->_searchBar setPositionAdjustment:UIOffsetMake(0, 0) forSearchBarIcon:UISearchBarIconSearch];

    }];

}

-(void)EndEdit:(UITextField*)textfiled{

    [UIView animateWithDuration:1 animations:^{

        [self->_searchBar setPositionAdjustment:UIOffsetMake(ComponentSearchOffset, 0) forSearchBarIcon:UISearchBarIconSearch];

    }];

}