Services: Add InspectorServer to reverse the direction of Inspector

This service daemon will act as an intermediary between the Inspector
program and the inspectable programs it wants to inspect.

Programs can make themselves available for inspection by connecting
to /tmp/portal/inspectables using the Core::EventLoop RPC protocol.

Userland/Services/InspectorServer/InspectorServer.ipc

@@ -0,0 +1,10 @@
+endpoint InspectorServer
+{
+    greet() => ()
+
+    get_all_objects(i32 pid) => (String json)
+    set_inspected_object(i32 pid, u64 object_id) => (bool success)
+    set_object_property(i32 pid, u64 object_id, String name, String value) => (bool success)
+    identify(i32 pid) => (String json)
+
+}