* Move tenant.Service unit tests into its package
* Delete the top-level TenantService interface now that it's not used.
* Move helper funcs for setting up test stores into testing pkg
* Delete duplicate implementations scattered through the codebase
* Move error assertions into store-creation helpers
* fix(tenant): use rand org bucket id generator over snowflake in tenant service
* fix(tenant): update bucket test harness to create org via store instead of service
* refactor: migrator and introduce Store.(Create|Delete)Bucket
feat: kvmigration internal utility to create / managing kv store migrations
fix: ensure migrations applied in all test cases
* chore: update kv and migration documentation
Daniel Moran
George
Alirie Gray
Lyon Hill
Jonathan A. Sternberg