EES-5396 Sync public API OpenAPI changes with API docs

[ntsim]

This PR adds a syncing mechanism to ensure that OpenAPI changes in the public API are documented in the API docs.

To enable this:

1. The public API now generates its OpenAPI documents at build time using the Swashbuckle CLI.
2. We use oasdiff to diff between the OpenAPI documents used by the API docs and those generated by the public API.
3. If there are any changes in the diff, we fail the build pipeline as this means there are undocumented changes.
4. To resolve any undocumented changes, developers need to copy over any changes from the public API to the relevant OpenAPI document in the API docs.

Once this diff has been resolved, the build can pass and deployment can proceed.

The API docs deployment has now been adjusted so that they are built during the build itself. We need to do this as

Related changes

• Removed /api prefix from openapi-v1.json in the API docs.
• Moved Swagger config into public API's Startup to enable the Swashbuckle CLI to work.

Other changes

• Disabled Swagger UI in non-dev environments (i.e. test, pre-prod, prod). This is consistent with our other backend APIs and avoids any problems from hosting the Swagger UI (it's expensive to generate).

[duncan-at-hiveit]

Nitpick but should ran be run?