Fix issues with showing code pasting URL

- use common signal for posting output for fileshare protocol, so it
  correctly behaves wrt the settings
- flash even when not opening the output pane when showing the output
- MessageManager::writeDisrupting should switch the output pane even if
  another output pane is currently open (which enforced with
  IOutputPane::WithFocus)

Fixes: QTCREATORBUG-26975
Change-Id: I51586eaca826f81f7e72f147fce7e72cbf639c6c
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/coreplugin/messagemanager.cpp

@@ -70,7 +70,7 @@ static void showOutputPane(Flag flags)
         m_messageOutputWindow->flash();
         break;
     case Core::Flag::Disrupt:
-        m_messageOutputWindow->popup(IOutputPane::ModeSwitch);
+        m_messageOutputWindow->popup(IOutputPane::ModeSwitch | IOutputPane::WithFocus);
         break;
     }
 }

src/plugins/cpaster/cpasterplugin.cpp

@@ -329,7 +329,7 @@ void CodePasterPluginPrivate::finishPost(const QString &link)
     if (m_settings.displayOutput.value())
         MessageManager::writeDisrupting(link);
     else
-        MessageManager::writeSilently(link);
+        MessageManager::writeFlashing(link);
 }
 
 // Extract the characters that can be used for a file name from a title

src/plugins/cpaster/fileshareprotocol.cpp

@@ -208,6 +208,6 @@ void FileShareProtocol::paste(
         return;
     }
 
-    Core::MessageManager::writeSilently(tr("Pasted: %1").arg(saver.filePath().toUserOutput()));
+    emit pasteDone(saver.filePath().toUserOutput());
 }
 } // namespace CodePaster