WebContent+LibWeb/CSS: Add debug request to dump CSS errors

Author: https://github.com/AtkinsSJ
Commit: 1adddb158a
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/5576

Libraries/LibWeb/CSS/Parser/ErrorReporter.cpp

@@ -64,4 +64,13 @@ void ErrorReporter::report(ParsingError&& error)
     m_errors.set(move(error), { .occurrences = 1 });
 }
 
+void ErrorReporter::dump() const
+{
+    // TODO: Organise this in some way?
+    dbgln("{} CSS errors reported:", m_errors.size());
+    for (auto const& [error, metadata] : m_errors) {
+        dbgln("- {} ({} occurrences)", serialize_parsing_error(error), metadata.occurrences);
+    }
+}
+
 }