[UI] Create generic component for "identity"

[alexsland]

• A modal
• with a "X" to dismiss in top right corner
• with an avatar
• with a name
• with space for eventual additionnal information under the name
• with 3 tabs (for now : qr code, public key & fingerprint)
• eventually with buttons under

For "my identity", when I want to consult my own QR code etc :

When I add a contact :

• When I click on a link to add a contact (deep link)
• When I click on a pending request
• When I scan a QR code
• When I enter a public key