Fix: ColorButtons in settings don't respect search (#2073)

Prior to this commit, adding a ColorButton to a SettingsLayout via
`SettingsLayout::addColorButton` lead to the button not respecting
search queries. This is because they are not added to the layout in a
Group. This commit fixes the behavior, causing color buttons to behave
like every other settings widget.

src/widgets/settingspages/GeneralPage.cpp

@@ -189,6 +189,9 @@ ColorButton *SettingsLayout::addColorButton(
             });
         });
 
+    this->groups_.back().widgets.push_back({label, {text}});
+    this->groups_.back().widgets.push_back({colorButton, {text}});
+
     return colorButton;
 }