Create new overview page

[acelaya]

Summary

Currently, after connecting to a server, you see the list of short URLs.

Change that, making the default page a new one including:

• Some cards with general values: total amount of visits, total amount of links, total amount of tags...
• Overview with most recent links (last 5, for example), with link to the full list.
• CTA for quick short URL creation (just the URL and tags), and "advanced" link to the section to create short URLs with more metadata. It should be uncollapsed always.