Update `ccao.class_dict` table

[dfsnow]

The ccao.class_dict table in Athena is now relied on heavily for dbt tests and other references. However, it hasn't actually been touched in awhile and needs a good update. Here's what I'm thinking:

• The class_dict table should be the internal source-of-truth for our class definitions. It should be the thing we reference in all documentation and tests.
• We need to update class_dict to include new classes used in iasWorld (OA2, suffix letters, etc.)
• I'll add the dictionary to PTAXSIM once it's finished, we can also add it to Open Data.
• We should change the class_dict CSV to a dbt seed, as in https://github.com/ccao-data/data-architecture/pull/348

@wrridgeway can do the legwork to find and collate the class codes, descriptions, and LoAs. @jeancochrane can do the technical work to update tests, checks, and the seed.

This is a ton of work, so feel free to break it up into multiple issues.

CC @ccao-jardine

[dfsnow]

This was effectively closed by #397, with LoA stuff covered by #420.