LibWeb: Style font-variant-* css properties

Author: https://github.com/jdahlin
Commit: 1c42d6831b
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2197
Reviewed-by: https://github.com/AtkinsSJ
Reviewed-by: https://github.com/gmta ✅
Reviewed-by: https://github.com/kalenikaliaksandr
Reviewed-by: https://github.com/tcl3

Libraries/LibGfx/Font/FontVariant.h

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2024, Johan Dahlin <jdahlin@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Optional.h>
+#include <AK/StringView.h>
+#include <AK/Vector.h>
+
+#pragma once
+
+namespace Gfx {
+
+struct FontVariantAlternates {
+    bool historical_forms { false };
+};
+
+struct FontVariantEastAsian {
+    enum class Variant {
+        Unset,
+        Jis78,
+        Jis83,
+        Jis90,
+        Jis04,
+        Simplified,
+        Traditional
+    };
+    enum class Width {
+        Unset,
+        Proportional,
+        FullWidth
+    };
+
+    bool ruby = false;
+    Variant variant { Variant::Unset };
+    Width width { Width::Unset };
+};
+
+struct FontVariantLigatures {
+    enum class Common {
+        Unset,
+        Common,
+        NoCommon
+    };
+    enum class Discretionary {
+        Unset,
+        Discretionary,
+        NoDiscretionary
+    };
+    enum class Historical {
+        Unset,
+        Historical,
+        NoHistorical
+    };
+    enum class Contextual {
+        Unset,
+        Contextual,
+        NoContextual
+    };
+    bool none = false;
+    Common common { Common::Unset };
+    Discretionary discretionary { Discretionary::Unset };
+    Historical historical { Historical::Unset };
+    Contextual contextual { Contextual::Unset };
+};
+
+struct FontVariantNumeric {
+    enum class Figure {
+        Unset,
+        Lining,
+        Oldstyle
+    };
+    enum class Spacing {
+        Unset,
+        Proportional,
+        Tabular
+    };
+    enum class Fraction {
+        Unset,
+        Diagonal,
+        Stacked
+    };
+    bool ordinal = false;
+    bool slashed_zero = false;
+    Figure figure { Figure::Unset };
+    Spacing spacing { Spacing::Unset };
+    Fraction fraction { Fraction::Unset };
+};
+
+}