Add maildat columns to default.vw_pin_address

[wrridgeway]

This PR adds iasworld.maildat to default.vw_pin_address as the new source of mail_ columns. We keep columns from iasworld.owndat, but we rename these columns with an owner_ prefix. This allows us to avoid committing entirely to one table or the other and provide as much information to users as possible while being clear about the limitations of both sources of address data.

The only real nuance here is that maildat is not unique by pin and year when cur = 'Y' and deactivat is null like most iasworld tables. Instead we also need to depend on mailseq and choosing which value of mailseq to privilege in order to make maildat unique by pin and year (we take the max value) boiled down to trying to match up with what's displayed on the treasurer's website. Two example pins are below:

parid	taxyr	mailseq	maddr1
01124000010000	2024	0	665 SW 8TH STREET
01124000010000	2024	1	1475 S BARRINGTON RD
02221170250000	2024	0	935 W. KENILWORTH
02221170250000	2024	1	493 W HELEN RD

Updates have not changed row count, as expected:

with old as (
	select year,
		count(*) as old
	from default.vw_pin_address
	group by year
),
new as (
	select year,
		count(*) as new
	from z_ci_941_owndat_vs_maildat_default.vw_pin_address
	group by year
)
select old.year,
	old.old,
	new.new,
	old.old - new.new as diff
from old
	left join new on old.year = new.year
where old.old != new.new

returns nothing. and mail_address_full is largely non-null:

select year,
	count(*) as new
from z_ci_941_owndat_vs_maildat_default.vw_pin_address
where mail_address_full is not null
group by year

year	new
2026	1749105
2025	1749120
2024	1750955
2023	1766525
2022	1767234
2021	1766333
2020	1768219
2019	1767675
2018	1768100
2017	1767909
2016	1767301
2015	1765763
2014	1765389
2013	1765993
2012	1766926
2011	1766397
2010	1764226
2009	1756264
2008	1739854
2007	1711776
2006	1678523
2005	1648889
2004	1625030
2003	1603501
2002	1586382
2001	1571199
2000	1555196
1999	1540553

[wrridgeway]

@ccao-jardine Are you okay with the taxpayer/owner dichotomy I've gone with here?

[ccao-jardine]

@wrridgeway, yes! This is much clearer, provides frequently requested data, and provides more information while also remaining transparent about ongoing data quality issues.

[jeancochrane]

Looking great! A few small suggestions, plus one request to clean up the docs. I'll give this a final look once that's done.

[jeancochrane]

[Suggestion, required] It seems like many of these columns are shared with owndat, and they already have docs definitions in dbt/models/iasworld/columns.md. Do you mind taking a minute to replace these descriptions with {{ docs() }} calls wherever documentation already exists in columns.md, or wherever a column exists on owndat such that its description can be moved to columns.md?

[jeancochrane]

Thanks so much for the docs cleanup! A few tiny suggested tweaks, but otherwise this is good to go.