[Fix] Convert received Money.amount from string to number

[sle-c]

WHY are these changes introduced?

Money.amount type from GraphQL actually returns a string as a result of Decimal serialization in the Admin GraphQL schema.

See

https://shopify.dev/docs/api/functions/reference/cart-transform/graphql/common-objects/moneyv2
https://shopify.dev/docs/api/functions/reference/cart-transform/graphql/scalar#decimal-2024-10

• We want to keep the Money interface consistent in the app.

WHAT is this pull request doing?

• Catch responses from the Billing GraphQL API and convert all Money.amount type from string to number

Type of change

• Patch: Bug (non-breaking change which fixes an issue)
• Minor: New feature (non-breaking change which adds functionality)
• Major: Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have used pnpm changeset to create a draft changelog entry (do NOT update the CHANGELOG.md files manually)
• I have added/updated tests for this change
• I have documented new APIs/updated the documentation for modified APIs (for public APIs)

[lizkenyon]

TY!