Set limit of active banner skills

Under normal circumstances, you can only be affected by one banner skill at a time. Currently, there are no checks in place to ensure this behaviour. Any fix would also have to correctly set the limit of banner skills you can be affected by to two when having equiped the Perfidy unique chest armour.

该 issue 没有指定文件或测试。首先定位应用 banner 技能的 Lua 代码，以及对 Perfidy unique 胸甲的处理；跟踪活动 banner 技能的计数方式。完成标准是：普通构筑允许一个受影响的 banner 技能，而 Perfidy 允许两个，并且检查覆盖这两种情况。