Auth Widget: display full name in place on hoverover (+ Sign Out onclick)

[sssoleileraaa]

Description

Followup for #675

Show the full name of the user on hover-over when it's longer than what can be displayed in the Auth Widget. You can do this by displaying a popup that appears over the truncated name. On click, the auth dialog should include a link to sign out.

On-click the auth dialog should look like:

On-hover the auth dialog should look like that except without the "Sign Out" section with link.

[eloquence]

See this Zeplin link for the "Sign out" hover effect.

Note that per #850 this auth widget is intended to fully replace the current "Sign out" menu, not just when the username is truncated.

@ninavizz Could you add screenshots or link that show the full intended state transitions:

• auth widget before click
• auth widget on hover
• auth widget on hover if username is truncated (if different)
• auth widget on click
• auth widget on click after hover over elements in the widget