Move testing knowledge from community to microsoft layer

Relocates the six P1+P2 testing-domain articles (18 files: .md + .good.al + .bad.al each) from community/knowledge/testing/ to microsoft/knowledge/testing/ per maintainer request. Pure git-mv rename; no content or frontmatter changes.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

microsoft/knowledge/testing/handlers-enqueue-never-assert.bad.al

@@ -0,0 +1,29 @@
+codeunit 50405 "Test Enqueue Handler Bad"
+{
+    Subtype = Test;
+
+    [Test]
+    [HandlerFunctions('PostMessageHandler')]
+    procedure PostingShowsConfirmationMessage()
+    begin
+        RunPostingThatMessages();
+        // The verdict was delegated to the handler below — a failed
+        // expectation there may never surface as this test's result.
+    end;
+
+    local procedure RunPostingThatMessages()
+    begin
+        Message('Posting completed.');
+    end;
+
+    [MessageHandler]
+    procedure PostMessageHandler(Message: Text)
+    begin
+        // Asserting inside the handler: if this is wrong the failure can be
+        // swallowed by the Message call, leaving the test falsely green.
+        Assert.AreEqual('Posting completed.', Message, 'Unexpected confirmation message.');
+    end;
+
+    var
+        Assert: Codeunit "Library Assert";
+}