Allow user to assign tenant as resource to role

[sourabhaggrawal]

Motivation

Improve Tenant/Namespace resource assignment workflow.

• When assigning the resource to a role, it only let you choose from Namespace,SCHEMA,Functions but does not allow the user to select TENANT. A user should have ability to choose tenant for a role and assign the role to a user. Based on which the user should be able to see the tenant it is assigned with.

Modifications

• changes in this PR include below fixes.

1. Add TENANT as ResourceType along with Namepsace,Schema etc for Create/Edit Role.
2. Include only tenants as resource while preparing the response from api /tenants in TenantsController.
3. In Success LoginResponse, add the tenant as header which is assigned to user's role instead of tenant with user's name.

Verifying this change

• Make sure that the change passes the ./gradlew build checks.

[sourabhaggrawal]

HI @eolivelli @tuteng please take a look