New "Last Audit" page

[fargito]

Feature Description

Webpage test already provides a functionality to compare two tests, but the results can be a bit difficult to read. I think that displaying the key metrics of the last audit (or an aggregate of the last few audits) in a more user-friendly way would be very nice.

That is why I think a new page could be built to display the info about the latest audit.

It could use the same metric that are displayed on the main page and display their value.
It could also compare that value to the historic data, in order to show if the performance is improving or degrading