Replace Tenant-User Membership with default role

The Roles table will get a role with the name 'member' This will be immutable.

Role assignment will be done in a table called user-project-roles. It will have 3 columns: user_id, project_id, role_id
All entries in user-tenant-assignments will be copied into user-project-role. They will be given the role_id for the 'member' role.

group_project_metadata Will be normalized into the user-project-role table.

get_tenants_for user in the V2 Controller will query select distinct (project_id) from user-project-role where user_id = {user_id}

Comparable changes need to be made on the LDAP side. Tenants currently have users in the member attribute. They will no longer do that. Again, all LDAP installs will have a Member Role by default, and value of the members attribute will be moved to the RoleOccupant attribute for the default Schema