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>

community/knowledge/testing/handlers-enqueue-never-assert.good.al

@@ -1,36 +0,0 @@
-codeunit 50404 "Test Enqueue Handler Good"
-{
-    Subtype = Test;
-
-    [Test]
-    [HandlerFunctions('PostMessageHandler')]
-    procedure PostingShowsConfirmationMessage()
-    var
-        ActualMessage: Text;
-    begin
-        // [WHEN] the code under test posts and raises a Message
-        RunPostingThatMessages();
-
-        // [THEN] the body — not the handler — owns the verdict
-        ActualMessage := LibraryVariableStorage.DequeueText();
-        Assert.AreEqual('Posting completed.', ActualMessage, 'Unexpected confirmation message.');
-        LibraryVariableStorage.AssertEmpty();
-    end;
-
-    local procedure RunPostingThatMessages()
-    begin
-        // Stands in for the production routine that ends with a Message.
-        Message('Posting completed.');
-    end;
-
-    [MessageHandler]
-    procedure PostMessageHandler(Message: Text)
-    begin
-        // Capture only — never assert here.
-        LibraryVariableStorage.Enqueue(Message);
-    end;
-
-    var
-        Assert: Codeunit "Library Assert";
-        LibraryVariableStorage: Codeunit "Library - Variable Storage";
-}