LibWeb: Generate and use to_string(css_enum) functions

The only one that's actually used is for Repeat, but it's easy to
generate them so might as well. :^)

Meta/Lagom/Tools/CodeGenerators/LibWeb/GenerateCSSEnums.cpp

@@ -77,6 +77,7 @@ enum class ValueID;
         enum_generator.appendln("};");
         enum_generator.appendln("Optional<@name:titlecase@> value_id_to_@name:snakecase@(ValueID);");
         enum_generator.appendln("ValueID to_value_id(@name:titlecase@);");
+        enum_generator.appendln("StringView to_string(@name:titlecase@);");
         enum_generator.append("\n");
     });
 
@@ -156,6 +157,31 @@ ValueID to_value_id(@name:titlecase@ @name:snakecase@_value)
         VERIFY_NOT_REACHED();
     }
 }
+)~~~");
+
+        enum_generator.append(R"~~~(
+StringView to_string(@name:titlecase@ value)
+{
+    switch (value) {)~~~");
+
+        for (auto& member : members.values()) {
+            auto member_generator = enum_generator.fork();
+            auto member_name = member.to_string();
+            if (member_name.contains('='))
+                continue;
+            member_generator.set("member:css", member_name);
+            member_generator.set("member:titlecase", title_casify(member_name));
+
+            member_generator.append(R"~~~(
+    case @name:titlecase@::@member:titlecase@:
+        return "@member:css@"sv;)~~~");
+        }
+
+        enum_generator.append(R"~~~(
+    default:
+        VERIFY_NOT_REACHED();
+    }
+}
 )~~~");
     });
 

Userland/Libraries/LibWeb/CSS/StyleValue.h

@@ -72,22 +72,6 @@ inline Gfx::Painter::ScalingMode to_gfx_scaling_mode(CSS::ImageRendering css_val
     VERIFY_NOT_REACHED();
 }
 
-constexpr StringView to_string(Repeat value)
-{
-    switch (value) {
-    case Repeat::NoRepeat:
-        return "no-repeat"sv;
-    case Repeat::Repeat:
-        return "repeat"sv;
-    case Repeat::Round:
-        return "round"sv;
-    case Repeat::Space:
-        return "space"sv;
-    default:
-        VERIFY_NOT_REACHED();
-    }
-}
-
 enum class TransformFunction {
     Matrix,
     Translate,