refactor: Remove Leading Mention in Replies and Highlight Participated Threads (#4047)

src/providers/colors/ColorProvider.cpp

@@ -147,6 +147,20 @@ void ColorProvider::initTypeColorMap()
              std::make_shared<QColor>(
                  HighlightPhrase::FALLBACK_ELEVATED_MESSAGE_HIGHLIGHT_COLOR)});
     }
+
+    customColor = getSettings()->threadHighlightColor;
+    if (QColor(customColor).isValid())
+    {
+        this->typeColorMap_.insert({ColorType::ThreadMessageHighlight,
+                                    std::make_shared<QColor>(customColor)});
+    }
+    else
+    {
+        this->typeColorMap_.insert(
+            {ColorType::ThreadMessageHighlight,
+             std::make_shared<QColor>(
+                 HighlightPhrase::FALLBACK_THREAD_HIGHLIGHT_COLOR)});
+    }
 }
 
 void ColorProvider::initDefaultColors()

src/providers/colors/ColorProvider.hpp

@@ -14,6 +14,7 @@ enum class ColorType {
     RedeemedHighlight,
     FirstMessageHighlight,
     ElevatedMessageHighlight,
+    ThreadMessageHighlight,
 };
 
 class ColorProvider