Fixes layering issues brought by the FoV PR. (#63903)

* Fixed most (not all) incorrect planes and layers detected by the unit test.

code/modules/projectiles/projectile.dm

@@ -13,6 +13,7 @@
 	wound_bonus = CANT_WOUND // can't wound by default
 	generic_canpass = FALSE
 	blocks_emissive = EMISSIVE_BLOCK_GENERIC
+	layer = MOB_LAYER
 	plane = GAME_PLANE_FOV_HIDDEN
 	//The sound this plays on impact.
 	var/hitsound = 'sound/weapons/pierce.ogg'

code/modules/projectiles/projectile/special/curse.dm

@@ -1,6 +1,7 @@
 /obj/effect/ebeam/curse_arm
 	name = "curse arm"
 	layer = LARGE_MOB_LAYER
+	plane = GAME_PLANE_UPPER_FOV_HIDDEN
 
 /obj/projectile/curse_hand
 	name = "curse hand"
@@ -8,6 +9,7 @@
 	base_icon_state = "cursehand"
 	hitsound = 'sound/effects/curse4.ogg'
 	layer = LARGE_MOB_LAYER
+	plane = GAME_PLANE_UPPER_FOV_HIDDEN
 	damage_type = BURN
 	damage = 10
 	paralyze = 20