[Feature request]: Expo plugins

### Is there an existing issue for this?

- [x] I have searched the existing issues

### Use case

In the current setup, we need to prebuild and modify the native code for each platform on every build.

### Proposal

Introduce Expo plugins, which automatically modify the native source code during the `eas prebuild/build` process.
This concept is called [Continuous Native Generation](https://docs.expo.dev/workflow/continuous-native-generation/), and it makes it a lot easier for the apps to use an automated build pipeline.
Yet, this doesn't affect a bare React Native setup at all.