Git: Use side-by-side layout for Fixup Previous Commit

Similar to simple commit layout.

Change-Id: If9470d47159cba21f11aefc8e2cc4895d10ff409
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/git/gitsubmiteditorwidget.cpp

@@ -105,7 +105,7 @@ void GitSubmitEditorWidget::initialize(CommitType commitType,
         connect(m_logChangeWidget, &LogChangeWidget::activated,
                 this, &GitSubmitEditorWidget::show);
         logChangeLayout->addWidget(m_logChangeWidget);
-        insertTopWidget(logChangeGroupBox);
+        insertLeftWidget(logChangeGroupBox);
         m_gitSubmitPanelUi.editGroup->hide();
         hideDescription();
     }

src/plugins/vcsbase/submiteditorwidget.cpp

@@ -561,6 +561,11 @@ void SubmitEditorWidget::insertTopWidget(QWidget *w)
     d->m_ui.vboxLayout->insertWidget(0, w);
 }
 
+void SubmitEditorWidget::insertLeftWidget(QWidget *w)
+{
+    d->m_ui.splitter->insertWidget(0, w);
+}
+
 void SubmitEditorWidget::addSubmitButtonMenu(QMenu *menu)
 {
     d->m_submitButton->setMenu(menu);

src/plugins/vcsbase/submiteditorwidget.h

@@ -122,6 +122,7 @@ protected:
     virtual QString cleanupDescription(const QString &) const;
     virtual QString commitName() const;
     void insertTopWidget(QWidget *w);
+    void insertLeftWidget(QWidget *w);
     void addSubmitButtonMenu(QMenu *menu);
     void hideDescription();