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/Administration/AdminAddReagentEuiState.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using Content.Shared.Chemistry;
 using Content.Shared.Eui;
 using Robust.Shared.Serialization;
@@ -25,7 +26,7 @@ namespace Content.Shared.Administration
         {
             public bool CloseAfter;
             public ReagentUnit Amount;
-            public string ReagentId;
+            public string ReagentId = string.Empty;
         }
     }
 }

Content.Shared/Administration/AdminFlags.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 
 namespace Content.Shared.Administration
 {

Content.Shared/Administration/AdminFlagsHelper.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Numerics;

Content.Shared/Administration/AdminMenu/AdminMenuPlayerListRequest.cs

@@ -1,4 +1,5 @@
-using Lidgren.Network;
+#nullable enable
+using Lidgren.Network;
 using Robust.Shared.Network;
 
 namespace Content.Shared.Administration.AdminMenu

Content.Shared/Administration/PermissionsEuiState.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using Content.Shared.Eui;
 using Robust.Shared.Network;
@@ -11,15 +12,15 @@ namespace Content.Shared.Administration
     {
         public bool IsLoading;
 
-        public AdminData[] Admins;
-        public Dictionary<int, AdminRankData> AdminRanks;
+        public AdminData[] Admins = Array.Empty<AdminData>();
+        public Dictionary<int, AdminRankData> AdminRanks = new();
 
         [Serializable, NetSerializable]
         public struct AdminData
         {
             public NetUserId UserId;
-            public string UserName;
-            public string Title;
+            public string? UserName;
+            public string? Title;
             public AdminFlags PosFlags;
             public AdminFlags NegFlags;
             public int? RankId;
@@ -43,8 +44,8 @@ namespace Content.Shared.Administration
         [Serializable, NetSerializable]
         public sealed class AddAdmin : EuiMessageBase
         {
-            public string UserNameOrId;
-            public string Title;
+            public string UserNameOrId = string.Empty;
+            public string? Title;
             public AdminFlags PosFlags;
             public AdminFlags NegFlags;
             public int? RankId;
@@ -60,7 +61,7 @@ namespace Content.Shared.Administration
         public sealed class UpdateAdmin : EuiMessageBase
         {
             public NetUserId UserId;
-            public string Title;
+            public string? Title;
             public AdminFlags PosFlags;
             public AdminFlags NegFlags;
             public int? RankId;
@@ -70,7 +71,7 @@ namespace Content.Shared.Administration
         [Serializable, NetSerializable]
         public sealed class AddAdminRank : EuiMessageBase
         {
-            public string Name;
+            public string Name = string.Empty;
             public AdminFlags Flags;
         }
 
@@ -85,7 +86,7 @@ namespace Content.Shared.Administration
         {
             public int Id;
 
-            public string Name;
+            public string Name = string.Empty;
             public AdminFlags Flags;
         }
     }

Content.Shared/Administration/SetOutfitEuiState.cs

@@ -1,3 +1,4 @@
+#nullable enable
 using Content.Shared.Eui;
 using Robust.Shared.Serialization;
 using System;