Moved highlight row index numbers to enum (#3829)

Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/controllers/highlights/HighlightModel.hpp

@@ -25,7 +25,13 @@ public:
         COUNT  // keep this as last member of enum
     };
 
-    constexpr static int WHISPER_ROW = 1;
+    enum HighlightRowIndexes {
+        SelfHighlightRow = 0,
+        WhisperRow = 1,
+        SubRow = 2,
+        RedeemedRow = 3,
+        FirstMessageRow = 4,
+    };
 
 protected:
     // turn a vector item into a model row