Create Messages UI

[ambid17]

Create a scrollable message container that holds cards.

Each card contains the following:

• whether or not it has been read (indicated by background color)
• the subject of the message
• a button container that allows the message to be clicked

https://docs.google.com/presentation/d/1vfE7jIPs00GNssnICO6IIOfoGVqoD8w29HzplfKXNnQ/edit#slide=id.g77016eff7c_4_0