LibWeb: Add facilities to serialize EnvironmentSettingsObjects

This will be used to transfer information about the parent context to
DedicatedWorkers and future out-of-process Worker/Worklet
implementations for fetching purposes. In order to properly check
same-origin and other policies, we need to know more about the outside
settings than we were previously passing to the WebWorker process.

Userland/Libraries/LibWeb/HTML/Scripting/Environments.h

@@ -12,6 +12,7 @@
 #include <LibWeb/HTML/EventLoop/EventLoop.h>
 #include <LibWeb/HTML/Origin.h>
 #include <LibWeb/HTML/Scripting/ModuleMap.h>
+#include <LibWeb/HTML/Scripting/SerializedEnvironmentSettingsObject.h>
 
 namespace Web::HTML {
 
@@ -40,11 +41,6 @@ struct Environment {
     bool execution_ready { false };
 };
 
-enum class CanUseCrossOriginIsolatedAPIs {
-    No,
-    Yes,
-};
-
 enum class RunScriptDecision {
     Run,
     DoNotRun,
@@ -115,6 +111,8 @@ struct EnvironmentSettingsObject
 
     void disallow_further_import_maps();
 
+    SerializedEnvironmentSettingsObject serialize();
+
 protected:
     explicit EnvironmentSettingsObject(NonnullOwnPtr<JS::ExecutionContext>);