Distribution groups

Why is this needed?

With the addition of preview tracks, we’ve made it easier to stay up-to-date on a given track.

However, it should be possible to create tracks in the dashboard and add additional automation/properties to tracks.

Steps to address the need

Primarily, we want to add support for distribution groups. Teams should be able to create distribution groups in the dashboard and assign users present in the organization/emails to which new updates should be sent to.

We should also consider adding a Slack integration where new previews on a given track can send a message to a specific Slack channel, as specified by a user.

Additionally, if a user is signed in the Tuist iOS app, they should receive a notification when a new preview is available (they should be able to turn on/off such notifications).