Design state of conversation when selected

[antho1404]

When a conversation is selected, there is no way to identify it visually. We need to have an active state to it

https://github.com/liteflow-labs/chat/blob/80c5b81ce79ab9a3647a59d0ddbba11ae742fee5/src/components/ConversationsList/ConversationTile.tsx#L16