refactor(ext/node): untangle dependencies between js files (#18284)

Moving some code around in `ext/node` is it's a bit better well defined
and makes it possible for others to embed it.

I expect to see no difference in startup perf with this change.

cli/tools/repl/session.rs

@@ -507,6 +507,7 @@ impl ReplSession {
         deno_node::initialize_runtime(
           &mut self.worker.js_runtime,
           self.proc_state.options.has_node_modules_dir(),
+          None,
         )?;
         self.has_initialized_node_runtime = true;
       }