- Remove connect, escape-string-regexp, eslint-plugin-relay deps (#28171)

Summary:
Some dependencies don't need to be downloaded by consumers:

- `connect` is only used in RNTester, moved to dev dependencies
- `escape-string-regexp` is not used directly, removed
- `eslint-plugin-relay` was in both deps and dev deps, removed from deps

Overall, this results in node_modules being 3.3MB smaller on clean install.

cc cpojer as you may already be aware. Feel free to treat these as a reference when optimizing internal deps.

## Changelog

[Internal] [Changed] - Remove connect, escape-string-regexp, eslint-plugin-relay deps
Pull Request resolved: https://github.com/facebook/react-native/pull/28171

Test Plan: CI passes

Reviewed By: hramos

Differential Revision: D20097591

Pulled By: cpojer

fbshipit-source-id: 0800751996accf39fd777bc6458be19f66f436a3