Remove unused UnitTest1 class and empty test method

The `UnitTest1` class in the `DocumentOperator.Tests` namespace was removed, including the `Test1` method, which was an empty test marked with the `[Fact]` attribute. This cleanup suggests the test class is no longer needed or has been replaced by other tests.

DocumentOperator.Tests/UnitTest1.cs

@@ -1,11 +0,0 @@
-namespace DocumentOperator.Tests
-{
-    public class UnitTest1
-    {
-        [Fact]
-        public void Test1()
-        {
-
-        }
-    }
-}