[UI] Chat Room busyness calculation

[mimetic]

Feature / Issue

1. In the list of chatrooms, we use a business icon to show how much activity is happening in chat room. The calculations for which icon to show are as follows:

ActivityInChatroom()

• Returns [int] 1 through 5
• Count N, the number of messages created in the past 24 hours
• return 1 if N <= 10
• return 2 if N <= 30
• return 3 if N <= 100
• return 4 if N <= 700
• return 5 if N > 700

These numbers are best guesses and may change — I recommend putting them in an easy to change place, e.g. globals.

2. We also show the number of recent participants in the list of chats, P. P(X) = number of unique chatroom participants in previous X hours, e.g. 24 hours or 72 hours.

Acceptance criteria

• [ ] Function for Activity in Chatroom created for UI to use in the list of chats, to choose which icon to show.
• [ ] Function created for UI to use to show number of recent participants in chat room in previous X hours.