Add the page to submit the manual tests results for specific images types.

It renames some routes and methods to clearly state the function of the
pages and also adds a 'submitted' page to show a message after the tests
results submission.

The commit only includes the pages and forms but it doesn't enable the
functionality to submit tests results yet.

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