This commit adds the submission page located at the /submit route that
can be used to enter the information to submit a manual test report.

It also adds a submit button in the index page to access the page and
redirects to /login if user is not logged in.

This commit only includes the submission page but doesn't enable its
functionality yet.

Signed-off-by: Luis Araujo <luis.araujo@collabora.co.uk>