main/cdr: Copy over location information during a fork

When a CDR is forked, a new CDR is created and appended to the CDR chain for
the Party A. The forked CDR starts life off as a clone of the last
non-finalized for the particular Party A. In the past, merely copying over
the snapshots for Party A/Party B would be sufficient. However, as the CDRs
now contain cached information from Party A - specifically application/data,
context, and extension - we need to copy that over during a fork as well.

Huzzah for unit tests catching this when the context/extension were derived
from a cached value on the CDR instead of on Party A.
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Merged revisions 422769 from http://svn.asterisk.org/svn/asterisk/branches/12
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Merged revisions 422770 from http://svn.asterisk.org/svn/asterisk/branches/13


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@422771 65c4cc65-6c06-0410-ace0-fbb531ad65f3