[Story] Aggregated dashboard and projections for group of companies

👤 **As a** user
🙏 **I want** to be able to define a group of companies and give the group a name
🎯 **so that** I can view the dashboard and projections pages for the group.

### Acceptance Criteria :+1: / :-1:
The dashboard and projections contains the results of an aggregation of the transactions for all the companies in the group.