UI changes before release

[hai-ko]

• [x] Sign in page only MetaMask button and explain text
• [ ] Place holder view if there are no contacts
• [ ] After login show last conversation
• [x] Hide conversation in profile view of contact (unhide if contact is added again)
• [ ] Sort messages by last message send or received
• [x] Loading indication for add contact button
• [x] Change add contact button color to contact list color
• [x] Domain Config: input field to text after it is set
• [x] Domain Config: button design right side, color like contact list color
• [x] Domain Config: should be scrollable
• [x] Domain Config: should be accessible over own profile view
• [x] Domain Config: remove banner after config view is accessed for the first time
• [x] Update Favicon