[Multi-Tenant] Add `tenantId` to fees

[njlie]

Because fees aren't associated with a Wallet Address like Open Payments resources are, it becomes necessary to add a tenantId to them to determine which tenant that fee should be applied to.

• [ ] Require a tenantId to be passed into the feeService.create call
• [ ] Filter any getters on the fee service by tenantId, unless the requester is the operator of the Rafiki instance