read the production icons from sequences

this allows d2k to read them from DATA.R8 without trouble

mods/ra/rules/infantry.yaml

@@ -448,7 +448,6 @@ SNIPER:
 	Valued:
 		Cost: 700
 	Tooltip:
-		Icon: snipericon
 		Name: Sniper
 		Description: Elite sniper infantry unit.\n  Strong vs Infantry\n  Weak vs Vehicles
 	Buildable:
@@ -492,7 +491,6 @@ Zombie:
 	Valued:
 		Cost: 100
 	Tooltip:
-		Icon: zombicon
 		Name: Zombie
 		Description: Slow undead. Attacks in close combat.
 	Buildable:
@@ -519,7 +517,6 @@ Ant:
 	Valued:
 		Cost: 300
 	Tooltip:
-		Icon: anticon
 		Name: Giant Ant
 		Description: Irradiated insect that grew oversize.
 	Buildable:

mods/ra/rules/structures.yaml

@@ -5,7 +5,6 @@ MSLO:
 	Tooltip:
 		Name: Missile Silo
 		Description: Launches a devastating atomic bomb\nat a target location.\n  Special Ability: Atom Bomb\n\nMaximum 1 can be built
-		Icon: msloicon2
 	Buildable:
 		Queue: Defense
 		BuildPaletteOrder: 130
@@ -459,7 +458,6 @@ PBOX.E1:
 	Tooltip:
 		Name: Pillbox (Guns)
 		Description: Basic defensive structure.\n  Strong vs Infantry, Light Vehicles\n  Weak vs Tanks, Aircraft
-		Icon: PBOXICON
 	RenderBuilding:
 		Image: PBOX
 	RenderRangeCircle:
@@ -624,7 +622,6 @@ HBOX.E1:
 	Tooltip:
 		Name: Camo Pillbox (Guns)
 		Description: Hidden defensive structure.\n  Strong vs Infantry, Light Vehicles\n  Weak vs Tanks, Aircraft
-		Icon: HBOXICON
 	RenderBuilding:
 		Image: HBOX
 	RenderRangeCircle:

mods/ra/rules/vehicles.yaml

@@ -402,7 +402,6 @@ MNLY.AP:
 		Cost: 800
 	Tooltip:
 		Name: Minelayer (Anti-Personnel)
-		Icon: MNLYICON
 		Description: Lays mines to destroy unwary enemy units.\n  Unarmed
 	Health:
 		HP: 100
@@ -437,7 +436,6 @@ MNLY.AT:
 		Cost: 800
 	Tooltip:
 		Name: Minelayer (Anti-Tank)
-		Icon: MNLYICON
 		Description: Lays mines to destroy unwary enemy units.\n  Unarmed
 	Health:
 		HP: 100