Changed Alignment enum to have distinct values. Updated related code.

UnitTests/View/Layout/Pos.AlignTests.cs

@@ -0,0 +1,59 @@
+using Xunit.Abstractions;
+using static Terminal.Gui.Dim;
+using static Terminal.Gui.Pos;
+
+namespace Terminal.Gui.PosDimTests;
+
+public class PosAlignTests (ITestOutputHelper output)
+{
+    [Fact]
+    public void PosAlign_Constructor ()
+    {
+        var PosAlign = new PosAlign (Alignment.Justified);
+        Assert.NotNull (PosAlign);
+    }
+
+    [Theory]
+    [InlineData (Alignment.Left, Alignment.Left, true)]
+    [InlineData (Alignment.Centered, Alignment.Centered, true)]
+    [InlineData (Alignment.Left, Alignment.Centered, false)]
+    [InlineData (Alignment.Centered, Alignment.Left, false)]
+    public void PosAlign_Equals (Alignment align1, Alignment align2, bool expectedEquals)
+    {
+        var posAlign1 = new PosAlign (align1);
+        var posAlign2 = new PosAlign (align2);
+
+        Assert.Equal (expectedEquals, posAlign1.Equals (posAlign2));
+        Assert.Equal (expectedEquals, posAlign2.Equals (posAlign1));
+    }
+
+    [Fact]
+    public void PosAlign_ToString ()
+    {
+        var PosAlign = new PosAlign (Alignment.Justified);
+        var expectedString = "Align(groupId=0, alignment=Justified)";
+
+        Assert.Equal (expectedString, PosAlign.ToString ());
+    }
+
+    [Fact]
+    public void PosAlign_Anchor ()
+    {
+        var PosAlign = new PosAlign (Alignment.Left);
+        var width = 50;
+        var expectedAnchor = -width;
+
+        Assert.Equal (expectedAnchor, PosAlign.Anchor (width));
+    }
+
+    [Fact]
+    public void PosAlign_CreatesCorrectInstance ()
+    {
+        var pos = Pos.Align (Alignment.Left);
+        Assert.IsType<PosAlign> (pos);
+    }
+
+    // Tests that test Left alignment
+
+    // 
+}