[Contactor] Feature is usable even when org is not activated

## Problem

When an organization has been created and has not been fully activated, the contractor's features are still usable. This is incorrect.

## Expected behavior

The contractor feature is disabled when the org is not activated. You should not be able to invite a contractor.

Start by locating the contractor invitation entry point and the organization activation state checks in the HCB repository. Add a regression test for an organization that is not fully activated, then verify that inviting a contractor is rejected while the organization is inactive.

Written by the indexing model from the issue text.