Added 1.2 and 1.5 support, mod icon, DefaultValue/Key for FishSet/Table

Source/FisheryLib/Diagnostics/Guard.String.cs

@@ -2,7 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 
 #pragma warning disable CS8777

Source/FisheryLib/Diagnostics/Guard.cs

@@ -4,8 +4,9 @@
 
 using System.Diagnostics;
 using System.Runtime.CompilerServices;
+#if V1_2
 using JetBrains.Annotations;
-using NotNullAttribute = System.Diagnostics.CodeAnalysis.NotNullAttribute;
+#endif
 
 namespace FisheryLib.Utility.Diagnostics;
 

Source/FisheryLib/Diagnostics/ThrowHelper.cs

@@ -7,7 +7,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Threading;
-using JetBrains.Annotations;
+
 // ReSharper disable InconsistentNaming
 
 namespace FisheryLib.Utility.Diagnostics;