New endpoint to search in "your contact-information" by phone-number

[tba76]

Description

• Deliver a search endpoint GET /profile/api/v1/dashboard/organizations/{orgNumber}/contactinformation/phonenumber (route must be decided during the task) that returns all organisations where the phonenumber is registered.
• New index in table to support search by phonenumber
• Align the response schema with existing DashboardController payload conventions so the Support Dashboard can present contact data consistently

Acceptance criteria

• Authenticated callers with the Dashboard Maskinporten scope can retrieve organisations for any phonenumber present in "your contactinformation".
• Empty or missing organisation results in a successful response with an empty collection and no partial failures.
• Unauthenticated or insufficient-scope requests are rejected with 401/403 and audited.
• Contract examples are documented in Swagger/OpenAPI.