update card::add_effect() (#408)
update card::add_effect() (#408)

1. Check the event reserved for EFFECT_TYPE_CONTINUOUS.
2. The trigger effect in phase is "once per turn" by default.
mercury233/ygopro-core,Fluorohydride/ygopro-core,Fluorohydride/ygopro-core,mercury233/ygopro-core