CosmosClient: Adds CreateAndInitializeAsync Method

[asketagarwal]

Pull Request Template

Description

Adds a CreateAndInitializeAsync method in CosmosClient. This creates a new client and initializes the containers provided by warming up the caches and connections
Closes: #1706

Sample

using Microsoft.Azure.Cosmos;
List<(string, string)> containersToInitialize = new List<(string, string)>
                                     { ("DatabaseName1", "ContainerName1"), ("DatabaseName2", "ContainerName2") };
CosmosClient cosmosClient = await CosmosClient.CreateAndInitializeAsync("account-endpoint-from-portal", 
                                                                               "account-key-from-portal",
                                                                                containersToInitialize)

[ealsur]

LGTM. Left some questions and suggestions, non-blocking, but might be worth thinking about them.

[kirankumarkolli]

Replicating one for each CTOR is good if we can avoid in future.

[VTR-AReed]

Hello, how would this work with the newly added Always Encrypted as .WithEncryption() returns a new client.