DRS - New Feature Flag for Corps Integration

We used `enable-document-records` feature flag for Corps integration. However, since this flag is enabled across all environments (prod, dev, and test), we need introduce a new feature flag specifically for Corps integration.

This would help ensure that Entities team remains unaffected by the integration, as we could simply disable the flag if needed.
A new feature flag `enable-doc-service-integration` needs to be created:

- [ ] sbc-auth (https://github.com/bcgov/sbc-auth) @seeker25

And make sure we have `enable-document-records` feature flag is created across the following repos:

- [ ] business-create-ui (https://github.com/bcgov/business-create-ui) @severinbeauvais
- [ ] business-edit-ui (https://github.com/bcgov/business-edit-ui) @severinbeauvais
- [ ] business-filings-ui (https://github.com/bcgov/business-filings-ui) @severinbeauvais
- [ ] business-dashboard-ui (https://github.com/bcgov/business-dashboard-ui) @severinbeauvais
- [ ] lear (https://github.com/bcgov/lear) @argush3

Start by inspecting how feature flags are defined and consumed in sbc-auth, business-create-ui, business-edit-ui, business-filings-ui, business-dashboard-ui, and lear. Confirm the separation between enable-doc-service-integration and enable-document-records with the listed repository contacts. Done means the new flag exists in sbc-auth and the existing flag is present across the five specified repositories.

Written by the indexing model from the issue text.