* hoist `react-dom/server` imports to reduce module load time in nodejs
* simplify `reactRoot` detection condition by checking the streaming rendering API we're using. (if it doesn't existed, like react 17, then we won't enable `reactRoot`)
* Merge `__NEXT_CONCURRENT_FEATURES` into `__NEXT_REACT_ROOT` env var since they're identical now
### source changes
* Error dynamic suspense option in non concurrent mode, don't check react root anymore since they should be bound
### tests changes
* Remove duplicated rsc client test
* Merge type checking cases (`next/dynamic`)
* Remove blocking rendering tests cases since we should opt-in Fizz rendering when using React.lazy
* Remove some thrown promises cases, leverage the streaming component we had in RSC test
## Documentation / Examples
- [x] Make sure the linting passes
- [x] Errors have helpful link attached, see `contributing.md` (for #28165, #27611)
- [x] Update test case
Do not fallback to loadable component when `reactRoot` is enabled but without `concurrentFeatures`. Thus we can enable pure client suspense:
`fallback` is always rendered on server side, but client side can work with fully functional suspense.
Closes#28117
### Changes
#### Feature
* Adopt `React.lazy` into `next/dynamic`, enable it when `options.suspense` is `true`
* Support `next/dynamic` with `suspense=true` in SSR and SSG
#### Tests
| Scenario | Case | Behavior |
|:----:|:----:|:----:|
| basics | react 17 or 18 by default | dev/build error or pass |
| blocking rendering | `reactRoot: true` + `concurrentFeatures: false` | dev/build pass |
| concurrent rendering | `reactRoot: true` + `concurrentFeatures: true` | dev/build pass |
## Feature
- [x] Implements an existing feature request or RFC. Make sure the feature request has been accepted for implementation before opening a PR.
- [ ] Related issues linked using `fixes #number`
- [x] Integration tests added
- [ ] Documentation added
- [ ] Telemetry added. In case of a feature if it's used or not.
- [ ] Errors have helpful link attached, see `contributing.md`
