Allows users to create DMs by selecting groups as a target. It also allows adding user groups to an existing chat
- When creating the channel, it expands the user group and adds all its members with chat enabled to the channel.
- After creation, there's no difference between adding a group or adding its members individually.
- Users can add multiple groups and users simultaneously.
- There are UI validations; the member count preview updates according to the member count of added groups, and it does not allow users to add more members than SiteSetting.chat_max_direct_message_users."
Group channels will allow users to create channels with a name and invite people. It's possible to add people even after creation of the channel. Removing users is not yet possible but will be added in the near future.
Technically a group channel is `direct_message_channel` with a group attribute set to true on its direct message (chatable). This model might evolve in the future but offers much flexibility for now without having to rely on a complex migration.
The commit essentially consists of:
- a migration to set existing direct message channels with more than 2 users to a group
- a new message creator which allows to search, add members, and create groups
- a new `AddUsersToChannel` service
- a modified `SearchChatable` service
Jan Cernik
Joffrey JAFFEUX