[Multi-Tenant] Tenanted Assets

[njlie]

Because assets 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 asset belongs to.

• [ ] Add required tenantId column to assets table
• [ ] Acquire tenantId from request header and pass into asset service logic during graphql requests
• [ ] Add tenantId to database queries on assets

Prerequisites:

• https://github.com/interledger/rafiki/issues/3103
• https://github.com/interledger/rafiki/issues/2928

[njlie]

Closing as the new design for Multi-Tenancy no longer uses logical barriers for tenanted resources.