added file as reserved words for dotnet generators

Author: HugoMario

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/AbstractCSharpCodegen.java

@@ -90,7 +90,7 @@ public AbstractCSharpCodegen() {
                         // set "client" as a reserved word to avoid conflicts with IO.Swagger.Client
                         // this is a workaround and can be removed if c# api client is updated to use
                         // fully qualified name
-                        "Client", "client", "parameter",
+                        "Client", "client", "parameter", "File", "file",
                         // local variable names in API methods (endpoints)
                         "localVarPath", "localVarPathParams", "localVarQueryParams", "localVarHeaderParams",
                         "localVarFormParams", "localVarFileParams", "localVarStatusCode", "localVarResponse",
@@ -468,6 +468,14 @@ private void postProcessEnumRefs(final Map<String, Object> models) {
         }
     }
 
+    public CodegenModel fromModel(String name, Model model, Map<String, Model> allDefinitions) {
+        final CodegenModel codegenModel = super.fromModel(name, model, allDefinitions);
+        if (typeMapping.containsKey(name.toLowerCase()) && isReservedWord(name)) {
+            typeMapping.remove(name.toLowerCase());
+        }
+        return codegenModel;
+    }
+
     /**
      * Update codegen property's enum by adding "enumVars" (with name and value)
      *