Convert longer media varchar fields to text in the catalog database

[AetherUnbound]

Description

Related #4279, see that issue for the rationale.

Alter the audio and image tables in the catalog to convert the following fields from character varying to text in the underlying database:

• foreign_identifier
• foreign_landing_url
• url
• thumbnail
• creator
• creator_url
• title
• audio_set_foreign_identifier (audio only)

This will require crafting the migration steps for the catalog database by hand and applying them, then altering the SQL DDL for the tables to reflect this difference. The alters should look like this:

ALTER TABLE audio ALTER COLUMN title TYPE TEXT USING title :: TEXT;

Postgres uses the same underlying storage methods for both these types, so the conversion from one to the other should be extremely fast.

Note
This is blocked by #4311, as the target columns need to be expanded first before the source ones can, otherwise the data refresh will fail.

[sarayourfriend]

@WordPress/openverse-catalog is anyone able to write the migration for this?

[AetherUnbound]

I'll pick this up later this week if no one gets to it before me.