eHit_Deflect forcibly plays hit effects on units

[Iridar]

I created a Shield Block ability for a soldier class that uses Ballistic Shield secondary, along with a custom animation, but then realized that using eHit_Deflect in X2Effect_Persistent::ChangeHitResultForTarget to take advantage of that animation results in psionic particle effects being played whenever the soldier deflects an attack.

https://www.youtube.com/watch?v=8NHf_LEeNmc

My custom deflect animation has no particle effects in it, they are added in XComUnitPawn::PlayHitEffects.

[Iridar]

Implemented in #825, closed by #826