C#: Add test model for generic method

Author: koesie10

csharp/ql/test/utils/modeleditor/FrameworkModeEndpoints.expected

@@ -9,6 +9,7 @@
 | PublicClass.cs:50:17:50:28 | neutralStuff | GitHub.CodeQL | PublicClass | neutralStuff | (System.String) | true | PublicClass.cs | neutral |
 | PublicGenericClass.cs:7:17:7:21 | stuff | GitHub.CodeQL | PublicGenericClass`2 | stuff | (T) | false | PublicGenericClass.cs |  |
 | PublicGenericClass.cs:12:17:12:26 | stuff2`1 | GitHub.CodeQL | PublicGenericClass`2 | stuff2`1 | (T2) | false | PublicGenericClass.cs |  |
+| PublicGenericClass.cs:17:18:17:36 | summaryStuff`1 | GitHub.CodeQL | PublicGenericClass`2 | summaryStuff`1 | (TNode) | true | PublicGenericClass.cs | summary |
 | PublicGenericInterface.cs:7:10:7:14 | stuff | GitHub.CodeQL | PublicGenericInterface`1 | stuff | (T) | false | PublicGenericInterface.cs |  |
 | PublicGenericInterface.cs:9:10:9:19 | stuff2`1 | GitHub.CodeQL | PublicGenericInterface`1 | stuff2`1 | (T2) | false | PublicGenericInterface.cs |  |
 | PublicGenericInterface.cs:11:17:11:27 | staticStuff | GitHub.CodeQL | PublicGenericInterface`1 | staticStuff | (System.String) | false | PublicGenericInterface.cs |  |

csharp/ql/test/utils/modeleditor/FrameworkModeEndpoints.ext.yml

@@ -16,6 +16,7 @@ extensions:
       extensible: summaryModel
     data:
       - ["GitHub.CodeQL","PublicClass",true,"summaryStuff","(System.String)","","Argument[0]","ReturnValue","taint","manual"]
+      - ["GitHub.CodeQL","PublicGenericClass<T,T2>",true,"summaryStuff<TNode>","(TNode)","","Argument[0]","ReturnValue","value","manual"]
 
   - addsTo:
       pack: codeql/csharp-all

csharp/ql/test/utils/modeleditor/PublicGenericClass.cs

@@ -13,4 +13,9 @@ public void stuff2<T2>(T2 arg)
     {
         Console.WriteLine(arg);
     }
+
+    public TNode summaryStuff<TNode>(TNode arg)
+    {
+        return arg;
+    }
 }