Define Tenant Boundaries for Data Isolation

### Dependencies
When this project moves to supporting more than one organization

### Overview
A tenant is a group of users. A tenant may want to isolate its data from other tenants for security, policy, legal, compliance reasons.

An example:
- OrgA is a client of HUU. OrgA provides two programs that carries out Host Homes and empty beds initiatives.
- OrgB is a client of HUU. OrgB provides five programs that carries out Host Homes and empty beds initiatives.
- OrgC is a client of HUU. OrgC provides one program that carries out Host Homes initiatives.

For data isolation, tenant could be defined as either the client organization or each of an organization's programs.

### Action Items
Research policies and regulations that organizations have to follow.
Define a tenant as an organization or as an organization's program. Ideally, choose one to define as the tenant.