chore: extract ConsoleMessage and FileChooser into its own module

[christian-bromann]

To support @jackfranklin's recent efforts in splitting up classes into their own modules here is a patch to do this for ConsoleMessage and FileChooser. It also starts to extract types into a single module and define them as types instead of interfaces.

[jackfranklin]

Nice, thanks for helping out! :)

I'd like to think about interfaces vs types and pick one and probably put some of the types back into the modules that own them (see the other comment) but once that's done I think this LGTM!

[christian-bromann]

Can we rerun 3173.3 Unit tests [with coverage]: Linux/Chromium, seems like a flake.

[jackfranklin]

@christian-bromann it's not a flake, it's because the references to these classes in src/api.ts are now invalid. Would you mind updating those please?