Support consumer subscribe multiple topics

[LeBW]

Describe what this PR does / why we need it

For now, the consumer can only subscribe one topic (destination).
Sometimes we need to subscribe multiple topics in one consumer (which is also one consumer binding in SCA).

In this PR, we can subscribe multiple topics in one consumer binding.

Does this pull request fix one issue?

Part of #2712.

Describe how to use it

1. Set multiplex in ConsumerProperties to true.
2. Write multiple topics in the destination with comma seperated, e.g., topic-1,topic-2.
3. The consumer binding will subscribe multiple topics.

Special notes for reviews

[steverao]

I didn't see the field of multiplex in your PR. Don't we need to set the field in ConsumerProperties？

[LeBW]

I didn't see the field of multiplex in your PR. Don't we need to set the field in ConsumerProperties？

multiplex should be set by the user in the application.yml if they want to enable this feature.