Add basic styling for printing of reports

We want to hide the web framework, but actually import some of the styling
from the base, when printing, to make things look reasonable.
Format query for readability
Fix "negative numbers in balance report" handling

It was exactly 100% reversed... Putting the negative number only in the
sum, and nothing else. Which meant the reports would never match if
anything on the "bottom half" of the balance report was changed during
the year.

This was probably introduced when making it work together with the year
closing functionality, so those have now been fully separated.

Hopefully this fixes all the reports...
Right-indent entries which are part of a group sum

This makes it more easy to read the report when a whole account group
has been folded.