Custom money type

[kgodey]

Problem

We've decided to implement a custom Mathesar money type that is an alias to NUMERIC types. Currency will be specified through display options.

Proposed solution

• Create a Money friendly type name in the service
• Create a MATHESAR_TYPES.MONEY type in the database that store currency amounts. The amount should be a NUMERIC type.
• Users should be able to use the API to change a column to MATHESAR_TYPES.MONEY if it's possible to do so.
• Automatic type inference during file import suggests MATHESAR_TYPES.MONEY when it makes sense to do so.
• Existing MATHESAR_TYPES.MONEY should be renamed to MATHESAR_TYPES.MULTICURRENCY_MONEY

Please note that this issue does not cover display options; a separate issue will be created for those once mathesar-foundation/mathesar-wiki#36 is finalized.

Additional context

• See discussion on Update number type to support custom currency format mathesar-wiki#36
• See relevant meeting notes

[mathemancer]

@kgodey It turns out that the previous custom type was called MATHESAR_TYPES.MATHESAR_MONEY. The reason for this is that it keeps the key money reserved for the default PostgreSQL MONEY type in a few auto-generated dictionaries. So, I've kept this for the new custom money type: It's called MATHESAR_TYPES.MATHESAR_MONEY.

[kgodey]

@mathemancer Sounds good.