[Multi-Tenant] Support using single database

[alecwhittington]

support using a single database

[seif]

@alecwhittington @chrisrichards any of you got an idea what this is about? Can you remind us?

[chrisrichards]

The existing multi tenant sample uses a separate database for each tenant, along with a master database for details of each tenant. I think this was to support multi tenancy by adding a key, e.g. tenant_id, to appropriate tables.