Made HighContrastDarkTheme return true on Theme#isHighContrast.

Made inactive titlebar color on macOS consistent with windows on HighContrastDarkTheme.

core/src/main/java/com/github/weisj/darklaf/theme/HighContrastDarkTheme.java

@@ -58,6 +58,11 @@ public class HighContrastDarkTheme extends Theme {
         return true;
     }
 
+    @Override
+    public boolean isHighContrast() {
+        return true;
+    }
+
     @Override
     public void loadUIProperties(final Properties properties, final UIDefaults currentDefaults) {
         super.loadUIProperties(properties, currentDefaults);

core/src/main/resources/com/github/weisj/darklaf/theme/high_contrast_dark/high_contrast_dark_platform.properties

@@ -22,7 +22,13 @@
 # SOFTWARE.
 #
 # suppress inspection "UnusedProperty" for whole file
+
+###Windows###
 Windows.TitlePane.inactiveBackgroundHover = 473724
 Windows.TitlePane.inactiveBackgroundClick = 594B39
 Windows.TitlePane.inactiveBackground      = 33210C
 Windows.TitlePane.inactiveForeground      = %textForegroundSecondary
+
+###MacOS###
+MacOS.TitlePane.inactiveBackground        = 33210C
+MacOS.TitlePane.inactiveForeground        = %textForegroundSecondary