Improve readability of pdf exports

There have been a few users noting poor readabilty of exported and printed PDF tables.

This MR adjusts the following:

• Use a darker red to indicate new elements (#cd0000 instead of #ff0000)
• Reduce table border width to 1.25 (small)/0.3 (wide)
• Add an extra padding within table cells

As the titlebox is defined by DIN EN 15016-1, the titlebox is not adjusted. A few minor corrections in accordance with the specification have also been applied (centering of text, adding missing dots after abbreviations).