Improved textEdit placeholder (#2149)

* Made colors a bit lighter

And also removed the tooltip from non-twitch channels

* Updated the changelog entry

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

src/widgets/splits/Split.hpp

@@ -97,6 +97,7 @@ private:
     void channelNameUpdated(const QString &newChannelName);
     void handleModifiers(Qt::KeyboardModifiers modifiers);
     void onAccountSelected();
+    void updateTooltipColor();
 
     SplitContainer *container_;
     IndirectChannel channel_;