making the running of epi plotting dependant on whether config had been provided. Modifying tests to stop using epi outputs which are no longer included

adding ability to set additional values to the run config from the command line args (if not already present in the config json)
modifying the epi processor to look for CalculationSpanDays in both the config json and the command line args, as preparation for use with the Epi fitting, which will pass calcspan as an arg

Also fixes 'issue date' in plots.

removing the need for a spatial points file in met_extractor assets to check the output dimensions, now compared to the input nc that created the results

removing processor_scraper.py, media scraper now lives in its own gitlab repo https://gitlab.developers.cam.ac.uk/gilligan-epid/wheat-rusts/media-scraper

This is handles by ews-epidemiology's model.py

rempoving project_handler from logging - not useful as multiple runs all compete and become collated with one another

making processor components pass their shortname in - rather than relying on the short_name map to know about all components