feat: extend connector_decorator

[hallvictoria]

Extend connector_trigger with explicit configuration for Poll and Webhook delivery modes. Adds skill file for adding a new decorator. Fixes https://github.com/Azure/azure-functions-bucees-planning/issues/1324

New arguments:

Argument	Description
delivery_mode	DeliveryMode.POLL or DeliveryMode.WEBHOOK; also accepts case-insensitive strings. Defaults to Webhook in the host when omitted.
connection	Connector connection setting. Required for Poll.
trigger_config_name	Trigger configuration name, including app-setting expressions. Required for Poll.
cardinality	Cardinality.ONE or Cardinality.MANY; also accepts case-insensitive strings. Optional; controls batching.
max_batch_size	Maximum events per batch. Optional for Poll.
max_concurrent_calls	Maximum concurrent calls. Optional for Poll.
target_pending_event_threshold	Optional pending-event threshold used for scaling.

Example:

@app.connector_trigger(
    arg_name="payload",
    delivery_mode=func.DeliveryMode.POLL,
    connection="ConnectorNamespace",
    trigger_config_name="%OnNewEmailTriggerConfigName%",
    cardinality=func.Cardinality.ONE,
    max_batch_size=1,
    max_concurrent_calls=1,
    target_pending_event_threshold=16,
)
def on_new_email(payload: str):
    logging.info("Received connector event: %s", payload)

Validation:
For Poll, the binding checks that connection and trigger_config_name, are not None, raising a ValueError listing missing arguments. Webhook and omitted delivery mode do not require these fields.

[Manvir Kaur (manvkaur)]

LGTM