Credits For v19

I've been working offline on a system for generating the credits for a
given postgres release, which derives most of its notion of what a name is
based on what passed for real names in previous year's release credits and
the name/email combinations that people use when sending to the hackers
list. When names without emails or emails without names are found, it
checks to see if that name/email was used with a proper pairing elsewhere.
From there I can build up correction lists to cover typos and misspellings.

The obvious gaps created by that sort of a system is that it doesn't
immediately recognize first-time contributors, and it doesn't recognize the
first time a typo happens, etc.

To that end, I've compiles three lists:

1. names that don't yet have a known "preferred name". 9 times out of 10
the name is fine, but I'd like to have the community take a pass at
correcting name spellings, proper name order, etc. There are 7 of these.

2. email addresses with no name associated. The program goes through the
pg-hackers mbox files from 2024 up through last month - so the email being
in this list is probably a sign that either the email address was
erroneous, or the sender does not want their name associated. There are 288
of these, but I assume a lot of them are duplicates.

3. Names in preferred_name+variant_name where evidence exists that the
preferred name is the spelling preferred by that person, with additional
rows pairing the preferred names with known variations/typos/etc. There are
320 of these, but some may be duplicates.

If you did work on v19, your name or email should be in one of those. Check
it out, post corrections and I'll coalesce them. Also, if you expected to
see your name (or somebody else's) but don't, reply with the commit
hash(es) that you feel are in error.