Switch AvoidContentManagerBadType to rely on DataLoader

Author: SinZ163

src/SMAPI.ModBuildConfig.Analyzer.DataGeneration/Program.cs

@@ -82,7 +82,7 @@ public void EmptyCode_HasNoDiagnostics()
         /// <param name="expression">The expression which should be reported.</param>
         /// <param name="netType">The net type name which should be reported.</param>
         /// <param name="suggestedProperty">The suggested property name which should be reported.</param>
-        [TestCase("Game1.content.Load<Dictionary<int, string>>(\"Data\\\\Fish\");", 0, "Data\\Fish", "System.Collections.Generic.Dictionary<System.Int32,System.String>", "System.Collections.Generic.Dictionary<System.String,System.String>")]
+        [TestCase("Game1.content.Load<Dictionary<int, string>>(\"Data\\\\Fish\");", 0, "Data\\Fish", "System.Collections.Generic.Dictionary<int, string>", "System.Collections.Generic.Dictionary<string, string>")]
         public void BadType_RaisesDiagnostic(string codeText, int column, string assetName, string expectedType, string suggestedType)
         {
             // arrange

src/SMAPI.ModBuildConfig.Analyzer.DataGeneration/SMAPI.ModBuildConfig.Analyzer.DataGeneration.csproj

@@ -0,0 +1,15 @@
+// ReSharper disable CheckNamespace, InconsistentNaming -- matches Stardew Valley's code
+// ReSharper disable UnusedMember.Global -- used dynamically for unit tests
+using System.Collections.Generic;
+
+namespace StardewValley
+{
+    /// <summary>A simplified version of Stardew Valley's <c>StardewValley.DataLoader</c> class for unit testing.</summary>
+    public static class DataLoader
+    {
+        public static Dictionary<string, string> Fish(LocalizedContentManager content)
+        {
+            return default!;
+        }
+    }
+}