#13 Reports are not theme aware

When using Typica on Linux with a dark theme, most of the elements change appropriately to match the theme. Reports do not and as a result most of the reports are basically unreadable on dark themes. The easiest fix here would be to just set a white background explicitly on reports, but it might be worth spending some time investigating the possibility of using the current theme colors at least for on screen reports.

While the current default style sheet for reports just sets the background color white, it seems likely that a more extensive style could use the current system settings to create reports that match the system theme. I’m not sure if this would be a good idea or not.

Another possible enhancement might be taking the default style sheet out of qrc_resources.cpp and making that easier for people to edit. This could be used for things like customizing report appearance to match corporate branding.