CustomField type for text

[zagnut007]

Is your feature request related to a problem? Please describe.
I'm trying to associate JSON objects with products and order lines in my shopping cart. Because these JSON objects are manipulated by the customer, they can grow in size and exceed the 64k limit on 'string' types in most databases.

Describe the solution you'd like
A new custom field type 'text' that would be able to handle a much larger size of text input. The default Admin UI handler/input type would be "textarea". In MySQL, the type would be 'longtext'. In Postgres/SQLite, the type would be 'text'.

Describe alternatives you've considered
I've been playing with the Asset server to handle the JSON objects, but the Admin UI is really expecting specific types of binary files and is causing issues when I'm trying to upload/manage JSON files associated with product variants. Also, uploading the JSON objects as binary files adds additional layers of complications in the GraphQL queries.