Add pulsing effect when invulnerable/intangible, make airdodge make the player intangible. (#75)

Reviewed-on: #75
Co-authored-by: Álex Román Núñez <eirexe@eirteam.moe>

src/fighter/state/air.rs

@@ -169,6 +169,8 @@ mod tests {
             air_dodge_duration: 0,
             air_dodge_velocity: FGi32::ZERO,
             air_dodge_decay: FGi32::ZERO,
+            air_dodge_intangible_duration: 29,
+            air_dodge_intangible_start: 4,
         }
     }