When a period has no data, but raw data, show a message #16790

Conditions when to apply this:

• For now only apply when "no segment" is select (report shows all visits)

When loading the reporting UI, or when selecting a different date, can we check in an API call if nb_visits=0? If that's the case, we also check if there's any visit during that period in log tables raw data. If that's the case, we could show an info message like this:

Where click on visits log would move the user to the "visits log". Could we also have a link that opens the date selector? Wording likely needs to be improved (didn't think too much about exact wording).

Maybe we would only do this extra API call if the date includes "today" as in other cases it should not be needed.