Add 'Show results' navbar

[aguilerapy]

With #96 we will have to redirect pages and this could cause loss of results links.

With #87 we will have two navbars on each page that allows us to choose whether to upload a file or give a URL.

So, we can add a third navbar 'Show results' in the last PR to merge. 'Show results' will show all the results links of our session, also, we can go between pages without losing those links.

[romifz]

Hi @aguilerapy,

I've created the 98-show-results branch with my implementation of this issue so far. I think it works well, but we need to remove from the session the files that are deleted from the server after 2 days. Can you please add this check? Let me know if you have any questions!