Admin group messages functionality

[bmamlin]

@bmamlin and @maurya to discuss options

[bmamlin]

Current approach allows messages between individuals by creating a row for each message with from/to users.

Proposed approach: null == everyone (broadcast)

• [ ] Adapt inbox to show any message to user or to null for anyone except admins (admins only see messages directed to them)
• [ ] Refactor message display so messages to null (everyone) do not provide a reply option.
• [ ] Refactor sending message to allow admins to choose "Broadcast to everyone" instead of naming a specific recipient and, when this is chosen, to create a message entry to null

This approach assumes we don't need the ability for admins to direct messages to a select group of users. This approach also assumes we don't need to know if a broadcast message has been read

• [ ] Ensure that recipients are unable to use the mechanism to directly communicate with other recipients

[bmamlin]

On further reflection, we will want individual users to be able to delete (or mark the message read), which would require a separate table to track individual. It will be easier to simply create a new row for each individual message.

The updated approach would be something like:

• [ ] We'll need a method to get all "current" users (e.g., exclude admins, inactive accounts)
• [ ] Add a method to broadcast that requires admin privilege, gets all current users, and sends a message to all of them
• [ ] Refactor the message sending UI to allow admins to select "Everyone" as the recipient and then confirms before sending.