FEAT: Create a Chat with User card

DEPENDS ON: #27

Once the users list in available in the project page :

• The connected user can see the card of other members on mouse hover
• Add an icon to send a message to one specific user
• Display a simple text input on click on icon
• Once the message is sent, a new chat is created with following name : "[SENDER full name] - [RECEIVER full name]"
• The receiver is notified the they've been contacted