UPDATE: Add a drawer to store user's workbooks

[dg-ac]

Hi there,

This PR aims to refresh the interface in the webapp by adding a collapsable drawer on the left side. Some reasons for this change:

• This will allow to list more workbooks
• Maybe will also allow search, and bulk actions (like multiple deletion)
• Declutter the current File Menu
• Use to list examples/templates (in the future)
• Use it to place sign in/sign out buttons (in the future)

There are still some missing things until this PR is ready to be merged:

• Ellipsis buttons should only be shown when hovering the list's items
• The 'Download workbook' button inside the ellipsis menu doesn't work for now
• Same for 'Delete workbook'

@nhatcher we can discuss this week.

[nhatcher]

Hi @dg-ac , as a first step could you add the drawer on its own folder?