Update shotgun sprites (#5120)

## About The Pull Request
Updates the renoster and the peacekeeper shotgun sprites, with sprites
taken from nova. Uses one of their shotgun variants edited slightly as
the new peacekeeper shotgun. Deleted the old sprites.

As a side note, I also deleted two icon states that were just pure solid
color, labeled "unused" and "old" respectfully. I have a feeling they
will not be missed.
## Why It's Good For The Game
I like their new sprites, and am really not a fan of our old peacekeeper
combat shotgun sprites.
## Proof Of Testing
works on my machine
<details>
<summary>Screenshots/Videos</summary>
Old sprites:
<img width="898" height="641" alt="image"
src="https://github.com/user-attachments/assets/26ef5648-7952-461e-b2ca-51f73716a2e2"
/>
<img width="1450" height="363" alt="image"
src="https://github.com/user-attachments/assets/f05ee569-6d48-40a8-b8e1-a920c2738778"
/>

New sprites(Left two are the combat shotgun):
<img width="395" height="126" alt="image"
src="https://github.com/user-attachments/assets/d542a7fa-5d9f-4785-9ab9-9032eb1666dc"
/>
<img width="95" height="57" alt="image"
src="https://github.com/user-attachments/assets/411484e3-3cea-4dee-a721-a677790a3e6e"
/>


</details>

## Changelog
🆑 UvvU
image: Modified the renoster and peacekeeper shotgun sprites
/🆑

modular_skyrat/modules/modular_weapons/code/company_and_or_faction_based/carwo_defense_systems/shotgun.dm

@@ -24,7 +24,8 @@
 	suppressed_sound = 'modular_skyrat/modules/modular_weapons/sounds/suppressed_heavy.ogg'
 	can_suppress = TRUE
 
-	suppressor_x_offset = 9
+	suppressor_x_offset = 7
+	suppressor_y_offset = -3
 
 	w_class = WEIGHT_CLASS_BULKY
 	slot_flags = ITEM_SLOT_BACK | ITEM_SLOT_SUITSTORE