BC Data Catalogue: Export full dataset

As an admin user, I need to export a csv of all register data so that I can send to others who can use it to populate systems that cannot consume the API.

This export will be done from the Data Catalogue.

Acceptance Criteria:

~~export to csv button exists (as per designs 2.0)~~
- the dataset below will be exported in csv format
- all fields that are on view screen will be in csv:
- Legal Name
- Display Name
- Phonetic Name
- Audio Link (url)
- Type
- ParkID
- Status
- Last Updated
- Effective date
- Search terms
- Notes
- Historical Legal Name
- Historical Display name
- Historical Phonetic Name
- Historical Audio Link
- Historical Effective Name
- Associated Sites - Name
~~display success toast if working (as per designs in 2.0)~~
~~display warning toast if not working (as per designs in 2.0)~~

Start by locating the Data Catalogue export entry point and the designs 2.0 referenced in the issue; no source file or test is named here. Confirm the view-screen fields and CSV behavior against the acceptance criteria, then verify that a complete export succeeds for the listed dataset.

Written by the indexing model from the issue text.