Add client factory method on provider & resource types

[tomas-pajurek]

Based on the developer feedback, instance factory methods like the following examples should be provided.

We should also consider removing static factory methods on clients (e.g. InMemoryBlobContainerClient.FromAccount) because they will become basically less developer-friendly equivalents of the new methods.

@DavidNepozitek @michal-zatloukal

Storage

InMemoryStorageProvider, InMemoryStorageAccount

• .CreateBlobServiceClient()
• .CreateBlobContainerClient()
• .CreateTableServiceClient()
• .CreateTableClient()

Probably avoid adding factory methods for blob-level clients.

Service Bus

InMemoryServiceBusProvider, InMemoryServiceBusNamespace

• .CreateServiceBusClient()
• .CreateServiceBusSender()
• .CreateServiceBusReceiver()

InMemoryServiceBusQueue, InMemoryServiceBusSubscription

• .CreateServiceBusReceiver()

InMemoryServiceBusQueue, InMemoryServiceBusTopic

• .CreateServiceBusSender()

Event Hub

InMemoryEventHubProvider, InMemoryEventHubNamespace, InMemoryEventHub

• .CreateProducerClient()
• .CreatePartitionReceiver()
• .CreateConsumerClient()

Key Vault

InMemoryKeyVaultProvider, InMemoryKeyVault

• .CreateSecretClient()