[Feature] explore removing references to the transactions table

### Is there an existing feature request for this?

- [X] I have searched the existing issues

### Describe the Feature

we've confirmed that monetary values stored in non-transaction tables (orders, order_lines, etc) are reported in the shop currency, so perhaps we don't need to use the transaction table's exchange rate data to get order totals.

### Describe alternatives you've considered

_No response_

### Are you interested in contributing this feature?

- [ ] Yes.
- [ ] Yes, but I will need assistance and will schedule time during your [office hours](https://calendly.com/fivetran-solutions-team/fivetran-solutions-team-office-hours) for guidance.
- [ ] No.

### Anything else?

_No response_