LibWeb: Abstract the LibProtocol ResourceLoader connection

This is the final component that required LibProtocol as a dependency
of LibWeb. With this, we can now remove the dependency, and LibWeb no
longer requires IPC to work :^)

Userland/Libraries/LibWebView/CMakeLists.txt

@@ -2,6 +2,7 @@ set(SOURCES
     DOMTreeModel.cpp
     ImageDecoderClientAdapter.cpp
     OutOfProcessWebView.cpp
+    RequestServerAdapter.cpp
     StylePropertiesModel.cpp
     WebContentClient.cpp
     WebSocketClientAdapter.cpp