refactor(cli): only add react and react-native when missing in prebuild

[byCedric]

Why

Fixes ENG-8480

This prevents accidental overwrites during expo prebuild. It's particularly painful in monorepos where users might want to use a specific react-native version, and not use the patch update.

How

Marked both react and react-native as "add when missing" packages. Meaning that if it's not defined, we still add it. But once it's defined, we only warn when the semver range DOES NOT intersect (react and react-native are defined as exact versions in the templates).

Note, that this still bumps expo and expo-splash-screen, which I think makes sense due to us releasing patch fixes regularly. But we can opt into fully disabling any bumps during prebuild in general.

Test Plan

See added tests, and:

• $ yarn create expo ./test-app && cd ./test-app
• Modify the React / React Native version to a lower patch/minor bump
• $ yarn expo prebuild
• This should warn with using current versions instead of the recommended react@<version>, react-native@<version>, it should not change the versions anymore.

Checklist

• Documentation is up to date to reflect these changes (eg: https://docs.expo.dev and README.md).
• Conforms with the Documentation Writing Style Guide
• This diff will work correctly for npx expo prebuild & EAS Build (eg: updated a module plugin).

[linear]

ENG-8480 Prebuild: stop modifying project dependencies

Starting with SDK 49, let's leave the react, react-native, and any other dependencies unchanged by default when running prebuild. Changing this versions during prebuild will occasionally break EAS Build for developers who using monorepos and miss out on doing a React Native version bump (and we often bump the patch version during an SDK cycle, so this can happen often).