Connect debugger before loading bundle (#53203)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/53203

Changelog: [internal]

This makes ReactHost connect the inspector immediately after creating the instance, aligned with how we do it on Android, instead of doing it as part of loading a bundle.

Reviewed By: rshest

Differential Revision: D79804004

fbshipit-source-id: b165520b0feb089fdfaa323413d697939c7ac794