Fix SPN support for refresh_semantic_model and takeover_item_ownership

[Copilot]

When running in a Fabric pipeline via Service Principal, refresh_semantic_model failed because it relied on sempy.fabric.refresh_dataset() / get_refresh_execution_details() — sempy functions that don't route through the SPN token provider set by service_principal_authentication.

Changes

• refresh_semantic_model: Replaces fabric.refresh_dataset() and fabric.get_refresh_execution_details() with direct calls to the Power BI Enhanced Refresh REST API via _base_api(client="fabric_sp"). Error extraction likewise uses the REST API instead of sempy.
• cancel_dataset_refresh: Replaces fabric.list_refresh_requests() with a direct REST API call; adds client="fabric_sp" to the delete request.
• get_semantic_model_refresh_history: Adds client="fabric_sp" to the existing _base_api call.
• takeover_item_ownership: Already used client="fabric_sp" correctly; docstring updated.
• All four functions now document SPN support. The visualize=True path (XMLA trace) is noted as requiring interactive user context.

Usage

with sempy_labs.service_principal_authentication(
    key_vault_uri="https://your-keyvault.vault.azure.net/",
    key_vault_tenant_id="tenant-id-secret",
    key_vault_client_id="client-id-secret",
    key_vault_client_secret="client-secret",
):
    labs.takeover_item_ownership(item="MyModel", type="SemanticModel", workspace="MyWorkspace")
    labs.refresh_semantic_model(dataset="MyModel", workspace="MyWorkspace")