Re-organise the modules

[davesnx]

As discussed here: https://github.com/reasonml/reason-react/issues/770

This file explains the new organisation of modules: https://github.com/reasonml/reason-react/blob/Unwrap-and-minimize-toplevels/src/README.md

• wrapped false and inlining most of the modules makes the interface a little cleaner for the users. On the other side, we have huge modules (which isn't so bad, but that it just my opinion)

• Moved all interface from React.rei into it's own module

• I didn't took any decision on ErrorBoundary, neither ReasonReactRouter. I got the feeling that we should rename those as SimpleErrorBoundary and SimpleRouter or similar. I would be fine to rename ReasonReactRouter to Router

[davesnx]

We would need to make a proper release notes with the module changes, but should be small.

[joprice]

@davesnx I'm seeing react-dom/test-utils and react-dom/server getting pulled in by vite during development with this change. Without some sort of change in melange to only import referenced submodules, maybe new modules like ReactDOMServer and ReactDOMTestUtils are necessary to avoid this?

[davesnx]

Splitting those into modules might make sense to avoid this issue. Would this problem fade away in production builds, where those modules would be gone with tree-shaking?

I would like to now how other bundlers handle dev/prod optimisations like this one, to decide if it's a good solution

[joprice]

I didn't get that far, since vite didn't like the require calls in the server-side commonjs modules. Not sure these particular ones will be shaken away, since I think purity of the module affect tree-shaking as well and would have to check that. I think either way, it's unexpected to pull in test utils or, in general, something you didn't intend to import, even in dev.