PM-755
Add entries with same lfn, pfn but with different pool/handle as a new entry.

Also handles removing case where an entry
like lfn-1 pfn-1 is updated to lfn-1 pfn-1 regex=true i.e. Entry get removed from m_lfn map and added in m_lfn_regex map.

i.e. Same LFN, PFN combination is not allowed with different states of the regex attribute value.