Feature: AsyncAPI Kafka partitions support

[Lancetnik]

Now, the following code

from faststream.specification import AsyncAPI
from faststream.kafka import KafkaBroker, TopicPartition

broker = KafkaBroker()

@broker.subscriber(partitions=[TopicPartition("test", 1)])
async def handler(): ...

docs = AsyncAPI(broker)

Just has no AsyncAPI representation

We should provides users with a correct schema in all subscriber options combinations, so

• [ ] Generate Channels for Kafka Subscriber in partitions case - https://github.com/airtai/faststream/blob/0.6.0/faststream/kafka/subscriber/specified.py#L20
• [ ] Respect partition in Kafka Publisher specifciation - https://github.com/airtai/faststream/blob/0.6.0/faststream/kafka/publisher/specified.py#L31
• [ ] Generate Channels for Confluent Subscriber in partitions case
• [ ] Respect partition in Confluent Publisher specification