TaskTree: Rename TaskAction into SetupResult

It's only used as a return value from group's or task's
setup handler. It instructs the running task tree on
how to proceed further.

It addresses the 21th point in the bugreport below.

Task-number: QTCREATORBUG-28741
Change-Id: I25802c76b9e7bc044c6a38197935798d2da9ad02
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: hjk <hjk@qt.io>

src/plugins/subversion/subversionclient.cpp

@@ -167,13 +167,13 @@ SubversionDiffEditorController::SubversionDiffEditorController(IDocument *docume
 
     const auto setupDescription = [this](Process &process) {
         if (m_changeNumber == 0)
-            return TaskAction::StopWithDone;
+            return SetupResult::StopWithDone;
         setupCommand(process, {"log", "-r", QString::number(m_changeNumber)});
         CommandLine command = process.commandLine();
         command << SubversionClient::AddAuthOptions();
         process.setCommand(command);
         setDescription(Tr::tr("Waiting for data..."));
-        return TaskAction::Continue;
+        return SetupResult::Continue;
     };
     const auto onDescriptionDone = [this](const Process &process) {
         setDescription(process.cleanedStdOut());