[babel-plugin-relay] Feature Request: Multiple project support like swc-relay

The config is just like what we did in swc-relay https://github.com/vercel/next.js/issues/64890

```
"relay": {
"root": "..",
"sources": {
"shared": "shared",
"web-app": "web-app"
},
"projects": {
"shared": {
"language": "typescript",
"output": "shared/__generated__",
"schema": "shared/schema.graphql"
},
"web-app": {
"base": "shared",
"language": "typescript",
"output": "web-app/__generated__",
"schema": "shared/schema.graphql"
}
}
},
```

Currently, it cannot have any workaround to make it happen. I would like to use multiple project config for relay.

Thanks