Git: Show full description on tooltip in commit chooser dialogs

Like Push to Gerrit, Rebase, Reset, Fixup Commit.

Fixes: QTCREATORBUG-24366
Change-Id: I0f596f84661a1a4f37fe971683cc0d985a6c9b1f
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/git/logchangedialog.h

@@ -42,6 +42,8 @@ QT_END_NAMESPACE
 namespace Git {
 namespace Internal {
 
+class LogChangeModel;
+
 // A widget that lists SHA1 and subject of the changes
 // Used for reset and interactive rebase
 
@@ -76,7 +78,7 @@ private:
     bool populateLog(const QString &repository, const QString &commit, LogFlags flags);
     const QStandardItem *currentItem(int column = 0) const;
 
-    QStandardItemModel *m_model;
+    LogChangeModel *m_model;
     bool m_hasCustomDelegate;
 };