Git: Add a toggle button for filter widget

Change-Id: If9680d1fc8a06f57f995a63095ad201fc1f3156b
Reviewed-by: André Hartmann <aha_1980@gmx.de>

src/plugins/git/giteditor.h

@@ -50,6 +50,9 @@ public:
     QString pickaxeValue() const;
     void refresh();
 
+signals:
+    void toggleFilters(bool value);
+
 private:
     void applyDiffChunk(const VcsBase::DiffChunk& chunk, bool revert);