Minor code refactoring

Author: Sergio0694

tests/CommunityToolkit.Mvvm.UnitTests/Collections/ObservableGroupTests.cs renamed to tests/CommunityToolkit.Mvvm.UnitTests/Collections/Test_ObservableGroup.cs

@@ -3,15 +3,14 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Collections.Specialized;
 using System.Linq;
 using CommunityToolkit.Mvvm.Collections;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommunityToolkit.Mvvm.UnitTests;
+namespace CommunityToolkit.Mvvm.UnitTests.Collections;
 
 [TestClass]
-public class ObservableGroupTests
+public class Test_ObservableGroup
 {
     [TestMethod]
     public void Ctor_ShouldHaveExpectedState()

tests/CommunityToolkit.Mvvm.UnitTests/Collections/ObservableGroupedCollectionTests.cs renamed to tests/CommunityToolkit.Mvvm.UnitTests/Collections/Test_ObservableGroupedCollection.cs

@@ -8,10 +8,10 @@
 using CommunityToolkit.Mvvm.Collections;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommunityToolkit.Mvvm.UnitTests;
+namespace CommunityToolkit.Mvvm.UnitTests.Collections;
 
 [TestClass]
-public class ObservableGroupedCollectionTests
+public class Test_ObservableGroupedCollection
 {
     [TestMethod]
     public void Ctor_ShouldHaveExpectedValues()

tests/CommunityToolkit.Mvvm.UnitTests/Collections/ObservableGroupedCollectionExtensionsTests.cs renamed to tests/CommunityToolkit.Mvvm.UnitTests/Collections/Test_ObservableGroupedCollectionExtensions.cs

@@ -3,14 +3,13 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Linq;
 using CommunityToolkit.Mvvm.Collections;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommunityToolkit.Mvvm.UnitTests;
+namespace CommunityToolkit.Mvvm.UnitTests.Collections;
 
 [TestClass]
-public class ObservableGroupedCollectionExtensionsTests
+public class Test_ObservableGroupedCollectionExtensions
 {
     [TestMethod]
     public void First_WhenGroupExists_ShouldReturnFirstGroup()

tests/CommunityToolkit.Mvvm.UnitTests/Collections/ReadOnlyObservableGroupTests.cs renamed to tests/CommunityToolkit.Mvvm.UnitTests/Collections/Test_ReadOnlyObservableGroup.cs

@@ -9,10 +9,10 @@
 using CommunityToolkit.Mvvm.Collections;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommunityToolkit.Mvvm.UnitTests;
+namespace CommunityToolkit.Mvvm.UnitTests.Collections;
 
 [TestClass]
-public class ReadOnlyObservableGroupTests
+public class Test_ReadOnlyObservableGroup
 {
     [TestMethod]
     public void Ctor_WithKeyAndOBservableCollection_ShouldHaveExpectedInitialState()

tests/CommunityToolkit.Mvvm.UnitTests/Collections/ReadOnlyObservableGroupedCollectionTests.cs renamed to tests/CommunityToolkit.Mvvm.UnitTests/Collections/Test_ReadOnlyObservableGroupedCollection.cs

@@ -12,10 +12,10 @@
 using CommunityToolkit.Mvvm.Collections;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace CommunityToolkit.Mvvm.UnitTests;
+namespace CommunityToolkit.Mvvm.UnitTests.Collections;
 
 [TestClass]
-public class ReadOnlyObservableGroupedCollectionTests
+public class Test_ReadOnlyObservableGroupedCollection
 {
     [TestMethod]
     public void Ctor_WithEmptySource_ShoudInitializeObject()