Add Relay Flight Build (#18242)

* Rename to clarify that it's client-only

* Rename FizzStreamer to FizzServer for consistency

* Rename react-flight to react-client/flight

For consistency with react-server. Currently this just includes flight
but it could be expanded to include the whole reconciler.

* Add Relay Flight Build

* Rename ReactServerHostConfig to ReactServerStreamConfig

This will be the config specifically for streaming purposes.
There will be other configs for other purposes.

scripts/shared/inlinedHostConfigs.js

@@ -78,11 +78,18 @@ module.exports = [
     isFlowTyped: true,
     isServerSupported: false,
   },
+  {
+    shortName: 'dom-relay',
+    entryPoints: ['react-flight-dom-relay', 'react-flight-dom-relay/server'],
+    paths: ['react-dom', 'react-flight-dom-relay'],
+    isFlowTyped: true,
+    isServerSupported: true,
+  },
   {
     shortName: 'custom',
     entryPoints: [
       'react-reconciler',
-      'react-flight',
+      'react-client/flight',
       'react-server',
       'react-server/flight',
     ],