Fetch company number from waste-organisations API on declaration detail

[NickBuckland]

AMCR-252

Summary

1. Fetch company number on submitted declaration detail (pending, accepted, cancelled) from the Waste Organisations API via \GET /organisations/{id}, matching the existing not-submitted path instead of reading \organisation.companiesHouseNumber\ on the obligations declaration embed (that field is not in the obligations API contract).
2. Extract shared \mapCompaniesHouseNumberFromWasteOrganisation\ and refactor waste-organisation detail field mapping into focused helpers (
   esolveWasteOrganisationRegistrationType, \mapRegistrationTypeToOrganisationType).
3. Add mock waste-organisation data for the \mockDetailData\ org UUID and unit tests covering the parallel \getOrganisation\ call and company number mapping for submitted declarations.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
90.9% Coverage on New Code
0.5% Duplication on New Code

See analysis details on SonarQube Cloud