ENH: Implement `vorsorgepauschale_ab_2005_bis_2009`, possibly earlier years, too.

[hmgaudecker]

150 adds Lohnsteuer, but the body of the above function is empty, earlier years are not considered.

[Eric-Sommer]

Legal reference for 2005: https://offenegesetze.de/veroeffentlichung/bgbl1/2004/33#page=3. It seems possible we can recycle the stuff from Einkommensteuer