Gun Code Modularization + Magazine Fed Shotgun (#751)

* Adds shotgun YAML files

* Adds shotgu ammo and magazine enum value, modularizes some projectile weapon methods

* Fixes guns consuming two bullets on fire

* Finishes shotgun behavior in Projectile Weapon Components

* Gun and ammo modularization

* Updates BallisticMagazineWeapons to be compatible with new AmmoWeapon

* Fixes shotgun spread angles, Fixes shogun YAML

* Gun documentation and ViewVariable specifications

* Removes todo messsage in gun code

* Default gun evenspread fix

* AmmoComponent Name fix

* Fixes Component name

* Projectile refactor code review fixes

Resources/Prototypes/Entities/Weapons/Ammunition/12g/ammunition.yml

@@ -0,0 +1,54 @@
+# Empty mags
+- type: entity
+  id: magazine_12g_empty
+  name: "12g magazine - empty"
+  parent: BaseItem
+  abstract: true
+  components:
+  - type: BallisticMagazine
+    caliber: A12g
+    magazine: A12g
+    capacity: 8
+  - type: Sprite 
+    netsync: false
+
+#Magazines
+- type: entity
+  id: magazine_12g_shotgun
+  name: "12g Magazine"
+  parent: magazine_12g_empty
+  components:
+  - type: BallisticMagazine
+    fill: ammo_casing_12g
+    caliber: A12g
+    magazine: A12g
+    capacity: 20
+  - type: Icon
+    sprite: Objects/Guns/Ammunition/Magazine/10mm/12mml.rsi
+    state: 12mml-1
+  - type: Sprite
+    sprite: Objects/Guns/Ammunition/Magazine/10mm/12mml.rsi
+    state: 12mml-1
+  - type: Appearance
+    visuals:
+    - type: BallisticMagazineVisualizer2D
+      base_state: 12mml
+      steps: 2
+
+# Casings
+- type: entity
+  id: ammo_casing_12g
+  name: "12g casing"
+  parent: BaseItem
+  components:
+  - type: BallisticBullet
+    caliber: A12g
+    projectile: pellet_12g
+    projectilesfired : 6
+  - type: Sprite
+    sprite: Objects/Guns/Ammunition/ammo_casing.rsi
+    state: s-casing
+    drawdepth: FloorObjects
+  - type: Icon
+    sprite: Objects/Guns/Ammunition/ammo_casing.rsi
+    state: s-casing

Resources/Prototypes/Entities/Weapons/Ammunition/12g/boxes.yml

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+# Empty boxes
+- type: entity
+  id: box_12g_empty
+  name: "12g box - empty"
+  parent: BaseItem
+  abstract: true
+  components:
+  - type: AmmoBox
+    caliber: A12g
+    capacity: 30
+  - type: Sprite 
+    netsync: false
+
+# Ammo boxes
+- type: entity
+  id: box_12g
+  name: "12g box"
+  parent: box_12g_empty
+  components:
+  - type: AmmoBox
+    fill: ammo_casing_12g
+    caliber: A12g
+    capacity: 30
+  - type: Icon
+    sprite: Objects/Guns/Ammunition/Boxes/10mm/box10mm.rsi
+    state: box10mm-1
+  - type: Sprite
+    sprite: Objects/Guns/Ammunition/Boxes/10mm/box10mm.rsi
+    state: box10mm-1
+  - type: Appearance
+    visuals:
+    - type: BallisticMagazineVisualizer2D
+      base_state: box10mm
+      steps: 2

Resources/Prototypes/Entities/Weapons/Ammunition/12g/projectiles.yml

@@ -0,0 +1,10 @@
+- type: entity
+  id: pellet_12g
+  name: 12g Pellet
+  parent: bullet_base
+  description: If you can see this you're dead!
+  components:
+  - type: Projectile
+    velocity: 20
+    damages:
+      Brute: 10

Resources/Prototypes/Entities/Weapons/Shotguns/shotguns.yml

@@ -0,0 +1,47 @@
+- type: entity
+  name: Shotgun
+  parent: BaseItem
+  id: BaseShotgun
+  description: A rooty tooty point and shooty.
+  abstract: true
+  components:
+  - type: Sound
+  - type: RangedWeapon
+    automatic: false
+    firerate: 20
+  - type: BallisticMagazineWeapon
+    caliber: A12g
+    evenspread : 40
+    magazines:
+    - A12g
+    default_magazine: magazine_12g_shotgun
+    auto_eject_magazine: false
+    sound_auto_eject: /Audio/Guns/EmptyAlarm/smg_empty_alarm.ogg
+    sound_magazine_in: /Audio/Guns/MagIn/smg_magin.ogg
+    sound_magazine_out: /Audio/Guns/MagOut/smg_magout.ogg
+    sound_empty: /Audio/Guns/Empty/empty.ogg
+    sound_gunshot: /Audio/Guns/Gunshots/smg.ogg
+
+- type: entity
+  name: Magazine Fed Shotgun
+  parent: BaseShotgun
+  id: MagazineFedShotgun
+  components:
+  - type: Sprite
+    netsync: false
+    sprite: Objects/Guns/SMGs/c20r.rsi
+    state: c20r-5
+  - type: Icon
+    sprite: Objects/Guns/SMGs/c20r.rsi
+    state: c20r-5
+  - type: Appearance
+    visuals:
+    - type: BallisticMagazineWeaponVisualizer2D
+      base_state: c20r
+      steps: 6
+  - type: Item
+    Size: 24
+    sprite: Objects/Guns/SMGs/c20r.rsi
+  - type: Item
+    Size: 24
+    sprite: Objects/Guns/SMGs/wt550.rsi