Refactor Charon database syncing and CharonSession object methods

Strange I thought this was changed in my latest code. We know memorise the entire flowcell name not the short version of it

(?P<seqrun_id>\d{6}_.+_\d{4}_.{10})')

should not be

(?P<seqrun_id>_\d{6}_.+_\d{4}_.+)')