Bug 1871514 - Improve macOS control colors. r=mac-reviewers,bradwerth

Instead of NSColor.textColor, use NSColor.controlTextColor, which is the color observed in native controls.

When these values were originally selected in bug 517412, the system colors were the same, but they have since diverged.

Differential Revision: https://phabricator.services.mozilla.com/D197125

widget/cocoa/nsLookAndFeel.mm

@@ -196,11 +196,6 @@ nsresult nsLookAndFeel::NativeGetColor(ColorID aID, ColorScheme aScheme,
                   ? GetColorFromNSColor(NSColor.controlTextColor)
                   : NS_RGB(0xFF, 0xFF, 0xFF);
       break;
-    case ColorID::Menutext:
-    case ColorID::Infotext:
-    case ColorID::MozSidebartext:
-      color = GetColorFromNSColor(NSColor.textColor);
-      break;
     case ColorID::Windowtext:
       color = GetColorFromNSColor(NSColor.windowFrameTextColor);
       break;
@@ -269,11 +264,14 @@ nsresult nsLookAndFeel::NativeGetColor(ColorID aID, ColorScheme aScheme,
     case ColorID::MozComboboxtext:
     case ColorID::Buttontext:
     case ColorID::MozButtonhovertext:
+    case ColorID::Menutext:
+    case ColorID::Infotext:
     case ColorID::MozDialogtext:
     case ColorID::MozCellhighlighttext:
     case ColorID::MozColheadertext:
     case ColorID::MozColheaderhovertext:
     case ColorID::MozColheaderactivetext:
+    case ColorID::MozSidebartext:
       color = GetColorFromNSColor(NSColor.controlTextColor);
       break;
     case ColorID::MozMacFocusring: