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.bad.al

@@ -1,29 +0,0 @@
-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";
-}