When `parseModel` suspends because of missing dependencies, it will exit and retry to parse later. However, in the relay implementation, the model is an object that we modify in place when we parse it, so when we we retry, part of the model might be parsed already into React elements, which will error because the parsing code expect a Flight model. This diff clones instead of mutating the original model, which fixes this error.
* Move files
* Update paths
* Rename import variables
* Rename /server to /writer
This is mainly because "React Server Server" is weird so we need another
dimension.
* Use "react-server" convention to enforce that writer is only loaded in a server
Luna Ruan