Fix crash related to highlights

A crash could occur when macro segments would be deleted while
highlighting of a segment was triggered.

src/macro-core/macro-action-edit.cpp

@@ -147,9 +147,9 @@ void MacroActionEdit::SetEntryData(std::shared_ptr<MacroAction> *data)
 	_entryData = data;
 }
 
-MacroSegment *MacroActionEdit::Data()
+std::shared_ptr<MacroSegment> MacroActionEdit::Data()
 {
-	return _entryData->get();
+	return *_entryData;
 }
 
 void AdvSceneSwitcher::AddMacroAction(int idx)

src/macro-core/macro-action-edit.hpp

@@ -44,7 +44,7 @@ private slots:
 	void ActionSelectionChanged(const QString &text);
 
 private:
-	MacroSegment *Data();
+	std::shared_ptr<MacroSegment> Data();
 
 	QComboBox *_actionSelection;
 

src/macro-core/macro-condition-edit.cpp

@@ -354,9 +354,9 @@ void MacroConditionEdit::DurationUnitChanged(DurationUnit unit)
 	(*_entryData)->SetDurationUnit(unit);
 }
 
-MacroSegment *MacroConditionEdit::Data()
+std::shared_ptr<MacroSegment> MacroConditionEdit::Data()
 {
-	return _entryData->get();
+	return *_entryData;
 }
 
 void AdvSceneSwitcher::AddMacroCondition(int idx)

src/macro-core/macro-condition-edit.hpp

@@ -75,7 +75,7 @@ private slots:
 
 private:
 	void SetLogicSelection();
-	MacroSegment *Data();
+	std::shared_ptr<MacroSegment> Data();
 
 	QComboBox *_logicSelection;
 	QComboBox *_conditionSelection;

src/macro-core/macro-segment.hpp

@@ -73,7 +73,7 @@ private:
 		BELOW,
 	};
 
-	virtual MacroSegment *Data() = 0;
+	virtual std::shared_ptr<MacroSegment> Data() = 0;
 	void ShowDropLine(DropLineState);
 
 	// The reason for using two separate frame widget each with their own