reports: get descriptive parameters from settings-file

[vicfabienne]

The reports (varaint and QC) are mentioning some settings and values in their descriptive markdwon part (e.g. the assembly number of the reference genome, some setting parameter that are good to know for an overview).
I think it should be able to change those values - so either grabbing them from the settings file or maybe providing as additional optional input? Or maybe an optional section in the settings file?

[rekado]

In order to be actionable, this issue needs a list of actual locations that you would like to change.

[jonasfreimuth]

This commit already makes a lot of things in the variantreport dynamic. But lofreq params are still not adjustable. Also I don't understand what parameters you mean in the QC report, @vfschumann. Are those already dealt with?