Added nullable to most Content.Shared files (#3238)

* Add nullable to some Content.Shared files.

* Use [NotNullWhen(true)]

* Undo adding now redundant !'s

* Forgot one

* Add a ton more nullable

* You can guess

* Fix some issues

* It actually compiles now

* Auto stash before merge of "null2" and "origin/master"

* I lied

* enable annotations -> enable

* Revert ActionBlockerSystem.cs to original

* Fix ActionBlockerSystem.cs

* More nullable

* Undo some added exclamation marks

* Fix issues

* Update Content.Shared/Maps/ContentTileDefinition.cs

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>

* Resolve some issues

* Remove unused method

* Fix more issues

* Fix more issues

* Fix more issues

* Fix more issues

* Fix issue, rollback SharedGhostComponent.cs

* Update submodule

* Fix issue, invert some if-statements to reduce nesting

* Revert RobustToolbox

* FIx things broken by merge

* Some fixes

- Replaced with string.Empty
- Remove some exclamation marks
- Revert file

* Some fixes

* Trivial #nullable enable

* Fix null ables

Co-authored-by: metalgearsloth <31366439+metalgearsloth@users.noreply.github.com>
Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>

Content.Shared/GameObjects/Components/Movement/IMoverComponent.cs

@@ -1,4 +1,5 @@
-using Robust.Shared.GameObjects;
+#nullable enable
+using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;
 

Content.Shared/GameObjects/Components/Movement/IRelayMoveInput.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using Robust.Shared.Players;
 
 namespace Content.Shared.GameObjects.Components.Movement

Content.Shared/GameObjects/Components/Movement/MovementSpeedModifierComponent.cs

@@ -1,4 +1,5 @@
-using Robust.Shared.Containers;
+#nullable enable
+using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
@@ -58,7 +59,7 @@ namespace Content.Shared.GameObjects.Components.Movement
         public static void RefreshItemModifiers(IEntity item)
         {
             if (item.TryGetContainer(out var container) &&
-                container.Owner.TryGetComponent(out MovementSpeedModifierComponent mod))
+                container.Owner.TryGetComponent(out MovementSpeedModifierComponent? mod))
             {
                 mod.RefreshMovementSpeedModifiers();
             }

Content.Shared/GameObjects/Components/Movement/SharedClimbableComponent.cs

@@ -1,4 +1,5 @@
-using Content.Shared.GameObjects.EntitySystems;
+#nullable enable
+using Content.Shared.GameObjects.EntitySystems;
 using Content.Shared.Interfaces.GameObjects.Components;
 using Robust.Shared.GameObjects;
 using Robust.Shared.Serialization;

Content.Shared/GameObjects/Components/Movement/SharedClimbingComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using Content.Shared.GameObjects.EntitySystems.ActionBlocker;
 using Content.Shared.Physics;
 using Robust.Shared.GameObjects;
@@ -12,14 +13,14 @@ namespace Content.Shared.GameObjects.Components.Movement
         public sealed override string Name => "Climbing";
         public sealed override uint? NetID => ContentNetIDs.CLIMBING;
 
-        protected IPhysicsComponent Body;
-        protected bool IsOnClimbableThisFrame = false;
+        protected IPhysicsComponent? Body;
+        protected bool IsOnClimbableThisFrame;
 
         protected bool OwnerIsTransitioning
         {
             get
             {
-                if (Body.TryGetController<ClimbController>(out var controller))
+                if (Body != null && Body.TryGetController<ClimbController>(out var controller))
                 {
                     return controller.IsActive;
                 }

Content.Shared/GameObjects/Components/Movement/SharedDummyInputMoverComponent.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using Robust.Shared.GameObjects;
 using Robust.Shared.Map;
 using Robust.Shared.Maths;

Content.Shared/GameObjects/Components/Movement/SharedSlipperyComponent.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using Content.Shared.GameObjects.Components.Mobs;
@@ -57,9 +58,9 @@ namespace Content.Shared.GameObjects.Components.Movement
             if (!Slippery
                 || Owner.IsInContainer()
                 ||  _slipped.Contains(entity.Uid)
-                ||  !entity.TryGetComponent(out SharedStunnableComponent stun)
-                ||  !entity.TryGetComponent(out IPhysicsComponent otherBody)
-                ||  !Owner.TryGetComponent(out IPhysicsComponent body))
+                ||  !entity.TryGetComponent(out SharedStunnableComponent? stun)
+                ||  !entity.TryGetComponent(out IPhysicsComponent? otherBody)
+                ||  !Owner.TryGetComponent(out IPhysicsComponent? body))
             {
                 return false;
             }
@@ -81,7 +82,7 @@ namespace Content.Shared.GameObjects.Components.Movement
                 return false;
             }
 
-            if (entity.TryGetComponent(out IPhysicsComponent physics))
+            if (entity.TryGetComponent(out IPhysicsComponent? physics))
             {
                 var controller = physics.EnsureController<SlipController>();
                 controller.LinearVelocity = physics.LinearVelocity * LaunchForwardsMultiplier;