Regression: High contrast themes fail to include Modena.css

[jperedadnr]

After #761, the high contrast themes don't work anymore.

To fix the issue with the user agent for third party controls, the modena.css stylesheet was removed:

 editorControllerTheme.getStylesheetURLs().stream()
                        .filter(s -> !EditorPlatform.isPlatformThemeStylesheetURL(s))
                            .forEach(themeStyleSheetsList::add);

but then setting the high contrast theme fails:

WARNING: Caught 'java.lang.ClassCastException: class java.lang.String cannot be cast to class javafx.scene.paint.Paint (java.lang.String is in module java.base of loader 'bootstrap'; javafx.scene.paint.Paint is in module javafx.graphics@24 of loader 'app')' while converting value for '-fx-background-color' from rule '*.titled-pane>*.title' in stylesheet jar:file:///~/.m2/repository/org/openjfx/javafx-controls/24/javafx-controls-24-mac-aarch64.jar!/com/sun/javafx/scene/control/skin/modena/yellowOnBlack.bss

because it can't read the variables set in modena.css/ .root {}, like -fx-accent.

Expected Behavior

High contrast themes work

Current Behavior

High contrast themes don't work

Steps to Reproduce

Open Scene Builder with an empty workspace
Add an Accordion container
Set a high contrast theme, the exceptions will show up, and only a few nodes will be properly styled.

Your Environment

Screenshots

Removing the filter added in #745 looks like: