Adds tenant_id, client_id, and client_secret to the Azure provider entry
in provider_create_fields.json so the credential add/edit modals and the
add-model form surface Service Principal auth as an alternative to api_key.
The Azure handler already reads these fields from litellm_params at request
time via get_azure_ad_token(); this change makes them inputtable from the
UI without code changes to the React components (the form is driven by
GET /public/providers/fields).
Ryan Crabbe
baeda235bb