Implement direct data return from controller classes

[ben-ryder]

Package Information: core @ *

Describe your feature
RIght now the controller methods that KangoJS binds to routes have no special handling which means you still have boilerplate code with sending responses and forwarding errors to next():

    @Route({
        httpMethod: HTTPMethods.POST,
        bodyShape: CreateNoteShape
    })
    async add(req: RequestWithUser, res: Response, next: NextFunction) {
        let newNote: NoteDto;

        try {
            newNote = await this.notesService.add(req.user.id, req.bodyDto);
        }
        catch (e) {
            return next(e);
        }

        return res.send(newNote);
    }

It would be great if the framework could absorb some of that repeated handling, so you could just do something like this instead and the returned data is sent in a response automatically and thrown errors are caught are handled:

    @Route({
        httpMethod: HTTPMethods.POST,
        bodyShape: CreateNoteShape
    })
    async add(req: RequestWithUser, res: Response, next: NextFunction) {
        return await this.notesService.add(req.user.id, req.bodyDto);
    }

Users should be able to still send a response manaully themselves though.

This will require a bit of discover work:

• How will error handling work in terms of unhandled promise rejections etc, will it work fine? (maybe user's should return promises directly, not return await?)
• Will core need to register the error handler the same way it does currently for auth and validation handlers?
• How can I make it posisble for users to still manually return a response as well as allowing for automatic response handling?

Is your suggestion related to any problems?
Controllers have a lot of repeated boilerplate code around response & error handling.

Additional context
n/a