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.

Meta/gn/secondary/Userland/Libraries/LibWeb/HTML/BUILD.gn

@@ -133,10 +133,12 @@ source_set("HTML") {
     "NavigatorBeacon.cpp",
     "NavigatorID.cpp",
     "Numbers.cpp",
+    "Origin.cpp",
     "PageTransitionEvent.cpp",
     "Path2D.cpp",
     "Plugin.cpp",
     "PluginArray.cpp",
+    "PolicyContainers.cpp",
     "PotentialCORSRequest.cpp",
     "PromiseRejectionEvent.cpp",
     "SelectItem.cpp",

Meta/gn/secondary/Userland/Libraries/LibWeb/HTML/Scripting/BUILD.gn

@@ -9,6 +9,7 @@ source_set("Scripting") {
     "ModuleMap.cpp",
     "ModuleScript.cpp",
     "Script.cpp",
+    "SerializedEnvironmentSettingsObject.cpp",
     "TemporaryExecutionContext.cpp",
     "WindowEnvironmentSettingsObject.cpp",
     "WorkerEnvironmentSettingsObject.cpp",