Cosmos: additional support for dedicated gateway SQLx features

We are currently missing two dedicated gateway features in the Python SDK:

**Bypass Dedicated Gateway**
Provide more control to customers by allowing them to choose whether to use the integrated cache or not. If set to `true`, the read will be served by the backend and won't be cached in the dedicated gateway.

ref: https://github.com/Azure/azure-sdk-for-java/pull/35865

**Shard Key**
Allow customers to optionally specify a shard key to use the new sharding feature.
Specifying the shard key will help route the request to an instance that has cached data for this shard or bypass the SQLx cache if correlated instance is down. If the shard key is not specified, it will fall back to the default behavior, which is randomly selecting an instance to serve the request.

ref: https://github.com/Azure/azure-sdk-for-java/pull/47796