Setup Openi internal reconciliation

Server-to-server endpoint used by openi-business when a company enables auto-reconciliation. Provisions an `openi-internal` data source and the `openi_invoices`/`openi_accounting_entries` datasets. Idempotent.

curl -X POST "https://example.com/v1/data-sources/openi/setup-reconciliation" \  -H "Content-Type: application/json" \  -d '{    "companyId": "8bb73d03-06b4-47c7-80c7-59301f770eda"  }'

{  "dataSourceId": "2b37f84c-d876-441e-9b27-0c3482a7c574",  "dataSourceCreated": true,  "datasets": [    {      "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",      "name": "string",      "kind": "string"    }  ]}