[Feature Request] Add a means of indicating a "node" project

[mike-north]

Currently, when the template of a project cannot be inferred via a big stack of conditions, create-react-app is chosen as a default.

https://github.com/codesandbox-app/codesandbox-importers/blob/079f9528017b2a73739f42ba29571f9f049c8119/packages/import-utils/src/create-sandbox/index.ts#L64

Particularly with the new server-side evaluation support, this may not be a reasonable or safe default anymore. Perhaps node should be the new default, with create-react-app being only reasonable in the presence of react or cra as a (dev)dependency?