Store the firecrest/bustard/gerald tuple in a new class PipelineRun

Store the firecrest/bustard/gerald tuple in a new class PipelineRun
This was because I found the <runfolder>/Config directory which contained
a useful file containing the real flowcell id.

I still need to get runfolder to copy the "important" files and to write
the output xml file somewhere other than the current directory.