[NEW] Support Broadcast

[rafaelks]

This feature allows the user to have channels/groups that are read-only with the possibility of other users being able to reply to the messages (in private).

Here’s how it works on the web:

Left user is the admin and right user is the common user

What needs to be done

1. Map the property broadcast in a channel/group: now each channel has a property called broadcast. It is a boolean and the default value is false. The value can not be present and the app needs to handle as the default value;
2. Members list must be hidden: when the room have the broadcast property as true, the members list must be hidden. Only visible for admins, moderators and owners of the rooms;
3. Normal users can’t send messages: the room is read-only for normal users. If the client already supports read-only rooms, no changes are required.
4. Reply button on each message: each message in a room needs to have a Reply button and when the user taps on the button, it needs to open the DM with the user who sent the message and “quoting” the message link. Example: if the user taps on the reply button on message with identifier abc123 we need to open the DM with this text filled on the text view: [ ](https://yourhost.com/direct/rafael.kellermann?msg=abc123).

How’s the style of the Reply button

• Font: same on the messages list, with “semi-bold” or “medium”
• Font-size: 15pt
• Text color: #1D74F5
• Border color: #1D74F5
• Background color: #FFFFFF
• Border radius: 4px