[WIP] Add notifications fragment and server side functionality

[JackMc]

What are you trying to accomplish with this PR?

Add support for getting list of notifications from the server. Currently it looks like this:

What's done?

• [x] Notifications server side (filtering by user)
• [x] Read notifications from server via endpoint
• [x] Notifications ListView
• [x] Sort notifications by recency

How is this accomplished?

Server and client side hackery, unfortunately.

Basically, I added a route /users/:id/notifications which returns all the notifications filtered appropriately for the user with that ID. I then used this route on the client side to construct Notification objects and use them in a ListView.

Checklist

• [ ] I have tested the changes in development
• [ ] I have received review from at least one other team member

[JackMc]

Merging this for demo purposes, we can work on the crash later.