Draft aggregate

[vil1]

Specify and implement commands/events/projections attached to the Draft aggregate.

See the wiki for the related events

The Draft aggregate is responsible for managing the edition of a talk proposal before it is submitted to the committee.

A Draft can be attached to at least one Speaker

Specific documentation of the Draft aggregate must be added to the corresponding wiki page

Question

Is it a good idea to have separate Draft and Proposal aggregates or should we merge these two notions (cf #9) ?