Concrete-Ening: Floor Tile Edition (#4106)

<!-- Write **BELOW** The Headers and **ABOVE** The comments else it may
not be viewable. -->
<!-- You can view Contributing.MD for a detailed description of the pull
request process. -->

## About The Pull Request
This PR proudly updates all the concrete tiles to better match the new
concrete walls created previously by @rye-rice! It also gives smooth
concrete as well as pavement unique variations so it doesn't look
repetitive!


![image](https://github.com/user-attachments/assets/36276b46-1249-4d1d-b9c2-dae39c0d76db)

In game screenshots:


![image](https://github.com/user-attachments/assets/073a9579-5752-4577-8e3c-a23cb1abb84e)


![image](https://github.com/user-attachments/assets/468df905-846c-40b9-8bdc-fca7ffa953f2)


![image](https://github.com/user-attachments/assets/d8dfeb7f-9e21-4fb9-bbc1-bf057cb8e970)

<!-- Describe The Pull Request. Please be sure every change is
documented or this can delay review and even discourage maintainers from
merging your PR! -->

## Why It's Good For The Game

![image](https://github.com/user-attachments/assets/7c87cd91-226f-4aa8-8e5a-99455def7f74)

<!-- Please add a short description of why you think these changes would
benefit the game. If you can't justify it in words, it might not be
worth adding. -->

## Changelog

:cl: PositiveEntropy
imageadd: Concrete, hexacrete and pavement tile sprites and varieties
have been updated!
/:cl:

<!-- Both :cl:'s are required for the changelog to work! You can put
your name to the right of the first :cl: if you want to overwrite your
GitHub username as author ingame. -->
<!-- You can use multiple of the same prefix (they're only used for the
icon ingame) and delete the unneeded ones. Despite some of the tags,
changelogs should generally represent how a player might be affected by
the changes rather than a summary of the PR's contents. -->

code/game/turfs/open/floor/conc_floor.dm

@@ -1,7 +1,9 @@
 /turf/open/floor/concrete
 	name = "concrete floor"
 	desc = "Cold, bare concrete flooring."
-	icon_state = "conc_smooth"
+	icon = 'icons/turf/floors/concrete.dmi'
+	icon_state = "conc_smooth_1"
+	base_icon_state = "conc_smooth"
 	broken_states = list("concdam_1", "concdam_2", "concdam_3", "concdam_4")
 	floor_tile = null
 	tiled_dirt = FALSE
@@ -15,6 +17,7 @@
 	// fraction ranging from 0 to 1 -- 0 is fully soft, 1 is fully hardened
 	// don't change this in subtypes unless you want them to spawn in soft on maps
 	var/harden_lvl = 1
+	var/has_variation = TRUE
 
 	var/shape_types = list(
 		/turf/open/floor/concrete,
@@ -31,6 +34,8 @@
 
 /turf/open/floor/concrete/Initialize()
 	. = ..()
+	if(has_variation)
+		icon_state = "[base_icon_state]_[rand(1,4)]"
 	check_harden()
 	update_appearance()
 
@@ -198,26 +203,32 @@
 
 /turf/open/floor/concrete/slab_1
 	icon_state = "conc_slab_1"
+	has_variation = FALSE
 
 /turf/open/floor/concrete/slab_2
 	icon_state = "conc_slab_2"
+	has_variation = FALSE
 
 /turf/open/floor/concrete/slab_3
 	icon_state = "conc_slab_3"
+	has_variation = FALSE
 
 /turf/open/floor/concrete/slab_4
 	icon_state = "conc_slab_4"
 	tiled_dirt = TRUE
+	has_variation = FALSE
 
 /turf/open/floor/concrete/tiles
 	icon_state = "conc_tiles"
+	has_variation = FALSE
 
 /turf/open/floor/concrete/reinforced
 	name = "hexacrete floor"
 	desc = "Reinforced hexacrete tiling."
 	icon = 'icons/turf/floors/hexacrete.dmi'
 	icon_state = "hexacrete-0"
 	base_icon_state = "hexacrete"
+	has_variation = FALSE
 	smoothing_flags = SMOOTH_BITMASK
 	smoothing_groups = list(SMOOTH_GROUP_TURF_OPEN, SMOOTH_GROUP_OPEN_FLOOR, SMOOTH_GROUP_FLOOR_HEXACRETE)
 	canSmoothWith = list(SMOOTH_GROUP_FLOOR_HEXACRETE)
@@ -273,7 +284,8 @@
 /turf/open/floor/concrete/pavement
 	name = "pavement"
 	desc = "The hot, coarse, and somewhat pavement. Vehicles driven on this are generally quiter than on traditional concrete, and is prefered for roadways."
-	icon_state = "pavement"
+	icon_state = "pavement_1"
+	base_icon_state = "pavement"
 	broken_states = null
 	shape_types = list(
 		/turf/open/floor/concrete/pavement,