Space/Chat Changes

[linhtphung]

• A chat is just a chat and don't show the nested icon. It's confusing.
• When you click on All chats, ALL chats should show up including direct messages. Spaces should not show up here, just chats.
• Spaces show up on the left panel on the web and in a separate tab on the phone (already exists)
  I don't feel like mockups are needed for this as they are small tweaks, but maybe those with design minds can try.

@wcjord @KhueDao1