Make Player invincible after damage while flashing (#491)
* Add EffectAnim and Hitbox to Player
- Hitbox is used to take damage from enemies when Player is colliding with them
To make enemy deal damage to Player you need to check `Enemy` or `Enemy Projectile` layer in collisions
If you want enemy to collide with player, but not deal any damage then only check `Player` mask in collisions
To control how much damage enemy is dealing you need to add `var damage: int` to enemy script
- EffectAnim used to play flashing animation when player is hit
At this time player is invincible for collisions hits (Hitbox monitoring is disabled)
* Fix false damage dealing from Enemies
- Remove BasicHitbox from BadCoin and MegaBoss:
Replace it with monitorable option for Laser and SpinBall areas
- Remove `Enemy` layer and mask `Player` for collision in:
Popcorn,Bub,DepthBlob,WallMech and FireMech,Luigi,Donk
* Add crouching for hitbox collision
