Utils: Provide a method to set total cell span for aspects

Only row span used currently in some base aspects, can be
extended once needed.

Used in the Perf config widget to correct recent change.

Change-Id: I37fae178cbfb8d493e0232e53e877d0e317ec9f2
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/perfprofiler/perfconfigwidget.cpp

@@ -117,10 +117,9 @@ PerfConfigWidget::PerfConfigWidget(PerfSettings *settings, QWidget *parent)
         Grid {
             m_settings->callgraphMode, m_settings->stackSize, nl,
             m_settings->sampleMode, m_settings->period, nl,
+            m_settings->extraArguments,
         },
 
-        Row { m_settings->extraArguments }, // FIXME: Align with above.
-
         Stretch()
     }.attachTo(this);
 }

src/plugins/perfprofiler/perfsettings.cpp

@@ -83,6 +83,7 @@ PerfSettings::PerfSettings(ProjectExplorer::Target *target)
     extraArguments.setSettingsKey("Analyzer.Perf.ExtraArguments");
     extraArguments.setDisplayStyle(StringAspect::DisplayStyle::LineEditDisplay);
     extraArguments.setLabelText(tr("Additional arguments:"));
+    extraArguments.setSpan(4);
 
     connect(&callgraphMode, &SelectionAspect::volatileValueChanged, this, [this](int index) {
         stackSize.setEnabled(index == 0);