AWS IoT enforces limits topic level and length. If 'aws_iot' is set on the policy, the topic limits will be enforced for AWS IoT.
Adding supports to MQTT wildcard support, topic to 256 chars, incorrect topic validation.
Use struct type instead of typedef to avoid it.
Adds client support for MQTT QoS0 and QoS1, compatible with AWS IoT Supports stream binding where independent client connections to the same endpoint can mux on a single tcp + tls connection with topic routing managed internally.
