splitting out logger creation in processor_base to allow processors to be called with a different logger setup (for example epi_fit)

Fix: remove Content column from output, because of the extra commas make it hard to read the files in.

adding wheat_group and wheat_group_display args to depo - this will be used when we start running different strains dynamically. For now we are hard-coding to "PROD". The "PROD" will appear in filenames, but not the image titles