App: DocumentObject - New full label member function

====================================================

Before this commit there is a function getFullName(), which
produces a string in the form document#objectname. For "document"
the real name of the document is taken, whereas for objectname it
is the initial name (Sketch, Sketch001), not the label.

The new function fo this commit, getFullLabel(), provides a string
documentlabel#documentobjectlabel, that are
probably easier to identify for end users.

src/App/DocumentObject.cpp

@@ -282,6 +282,16 @@ std::string DocumentObject::getFullName() const {
     return name;
 }
 
+std::string DocumentObject::getFullLabel() const {
+    if(!getDocument())
+        return "?";
+
+    auto name = getDocument()->Label.getStrValue();
+    name += "#";
+    name += Label.getStrValue();
+    return name;
+}
+
 const char *DocumentObject::getNameInDocument() const
 {
     // Note: It can happen that we query the internal name of an object even if it is not

src/App/DocumentObject.h

@@ -140,6 +140,8 @@ public:
     std::string getExportName(bool forced=false) const;
     /// Return the object full name of the form DocName#ObjName
     std::string getFullName() const override;
+    /// Return the object full label in the form DocName#ObjName
+    std::string getFullLabel() const;
     bool isAttachedToDocument() const override;
     const char* detachFromDocument() override;
     /// gets the document in which this Object is handled