update Lexicon.py to handle 3 or 4 count of /store/hidata/... lfn by YG

Hi, Seangchan & Eric:

Please review this pull request, We need it for CMSWEB October release. This patch updated Lexicon.py to handle lfns' that begin with /store/hidata.  We need it to read files from the missing parentage datasets. We cannot continue to fix the parentage until we have this new lexicon in production.

Thanks,
Yuyi