Migrate telemetry API tests to resource_* fixtures

Partially-implements bp resource-cleanup

Change-Id: I47e007ef70b79044d78c08b07b222183e1025f70
Drop OfficialClientManager from tenant isolation

Scenario tests use the tempest clients, so drop support for
OfficialClientManager from the tenant isolation classes.

Change-Id: I84638210043d376b4f4025a69751536651991293
Partially-implements: bp:tempest-client-scenarios
Merge "Drop OfficialClientManager from tenant isolation"
Merge "Migrate telemetry API tests to resource_* fixtures"