[Settings Tests] Migrate General Settings tests (#5753)

* added MSTest project

* migrated general settings tests

* enabled settings tests run in the build pipeline

* added tests

* move relay command class to separate file

* added a foldername parameter for general settings view model

src/core/Microsoft.PowerToys.Settings.UI.UnitTests/ModelsTests/BasePTModuleSettingsTest.cs

@@ -0,0 +1,53 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using Microsoft.PowerToys.Settings.UI.Lib;
+using Microsoft.PowerToys.Settings.UnitTest;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Newtonsoft.Json.Linq;
+using Newtonsoft.Json.Schema;
+
+namespace CommonLibTest
+{
+    [TestClass]
+    public class BasePTModuleSettingsTest
+    {
+        // Work around for System.JSON required properties:
+        // https://docs.microsoft.com/en-us/dotnet/standard/serialization/system-text-json-migrate-from-newtonsoft-how-to.
+        // Test also fails when the attributes are not initialized i.e they have null values.
+        [TestMethod]
+        [Obsolete]
+        public void ToJsonString_ShouldReturnValidJSONOfModel_WhenSuccessful()
+        {
+            // Arrange
+            string file_name = "test\\BasePTModuleSettingsTest";
+            string expectedSchemaText = @"
+                {
+                    '$schema': 'http://json-schema.org/draft-04/schema#',
+                    'type': 'object',
+                    'properties': {
+                    'name': {
+                        'type': 'string'
+                    },
+                    'version': {
+                        'type': 'string'
+                    }
+                    },
+                'additionalProperties': false
+                }";
+
+            string testSettingsConfigs = new BasePTSettingsTest().ToJsonString();
+            SettingsUtils.SaveSettings(testSettingsConfigs, file_name);
+            JsonSchema expectedSchema = JsonSchema.Parse(expectedSchemaText);
+
+            // Act
+            JObject actualSchema = JObject.Parse(SettingsUtils.GetSettings<BasePTSettingsTest>(file_name).ToJsonString());
+            bool valid = actualSchema.IsValid(expectedSchema);
+
+            // Assert
+            Assert.IsTrue(valid);
+        }
+    }
+}