LibWeb: Add CSSImportRule wrapper

Author: https://github.com/AtkinsSJ
Commit: 0cf8986a1e
Pull-request: https://github.com/SerenityOS/serenity/pull/13774

Userland/Libraries/LibWeb/CSS/CSSImportRule.idl

@@ -0,0 +1,10 @@
+#import <CSS/CSSRule.idl>
+#import <CSS/CSSStyleSheet.idl>
+#import <CSS/MediaList.idl>
+
+[Exposed=Window]
+interface CSSImportRule : CSSRule {
+    readonly attribute USVString href;
+    // [SameObject, PutForwards=mediaText] readonly attribute MediaList media;
+    [SameObject, ImplementedAs=style_sheet_for_bindings] readonly attribute CSSStyleSheet styleSheet;
+};