async_cluster: fix max_connections/ssl & improve args

- set proper connection_class if ssl = True
- pass max_connections/connection_class to ClusterNode
- recreate startup_nodes to properly initialize
- pass parser_class to Connection instead of changing it in on_connect
- only pass redis_connect_func if read_from_replicas = True
- add connection_error_retry_attempts parameter
- skip is_connected check in acquire_connection as it is already checked in send_packed_command

BREAKING:
- RedisCluster args except host & port are kw-only now
- RedisCluster will no longer accept unknown arguments
- RedisCluster will no longer accept url as an argument. Use RedisCluster.from_url
- RedisCluster.require_full_coverage defaults to True
- ClusterNode args except host, port, & server_type are kw-only now

Author: utkarshgupta137