Component for CosmosDB change feed

The case of "[tailing](https://microservices.io/patterns/data/transaction-log-tailing.html)" the database, subscribing to it's "[change feed](https://docs.microsoft.com/en-us/azure/cosmos-db/change-feed)" has a lot of possibilities.
Combining a state store and tailing would open up many scenarios.
Since the building blocks for supporting this scenario might be found in *bindings* or *pubsub*, it's a matter of implementation.
There is a lot of conceptual similarities with consuming Event Hub partitions.

I don't know what kind of support different go libraries and SDK has working with the CosmosDB change feed.

But I think this kind of components have a lot of potential if possible.

Review the existing bindings or pubsub components, then compare their consumption patterns with Event Hub partitions and the available Go libraries and SDKs. Done means defining a feasible component scope for subscribing to the CosmosDB change feed and combining it with a state store.

Written by the indexing model from the issue text.