Add highlighting of all messages from a certain user (#564)

* Rework to use controllers

* Rework to use controllers

* Add doHighlight

* Cherry pick?

* Fixes per PR

* Remove file

src/controllers/highlights/UserHighlightModel.hpp

@@ -0,0 +1,27 @@
+#pragma once
+
+#include <QObject>
+
+#include "common/SignalVectorModel.hpp"
+#include "controllers/highlights/HighlightPhrase.hpp"
+
+namespace chatterino {
+
+class HighlightController;
+
+class UserHighlightModel : public SignalVectorModel<HighlightPhrase>
+{
+    explicit UserHighlightModel(QObject *parent);
+
+protected:
+    // vector into model row
+    virtual HighlightPhrase getItemFromRow(std::vector<QStandardItem *> &row,
+                                           const HighlightPhrase &original) override;
+
+    virtual void getRowFromItem(const HighlightPhrase &item,
+                                std::vector<QStandardItem *> &row) override;
+
+    friend class HighlightController;
+};
+
+}  // namespace chatterino