Modularize Bicep deployment

[pauldotyu]

Is your feature request related to a problem? Please describe.
Currently the infrastructure as code is set to deploy all Azure resources as the default behavior. However, there may be scenarios where some of the Azure services are not needed for various demonstrations.

Describe the solution you'd like
In order to better support various demo scenarios, it would be best to modularize the deployment and deploy ancillary Azure services as needed based on Bicep input parameters. This is already being done with Azure Container Registry and we should look to take a similar approach with the other services.

We can start with the following boolean parameters:

• DEPLOY_AZURE_CONTAINER_REGISTRY deploys Azure Container Registry
• DEPLOY_WORKLOAD_IDENTITY deploys Azure Managed Identities for services that support it and enables workload identity and OIDC Issuer URL on AKS
• DEPLOY_AZURE_OPENAI deploys Azure OpenAI, the ai-service microservice, and configures workload identity if that option is set to true
• DEPLOY_AZURE_SERVICE_BUS deploys Azure Service Bus and configures workload identity if that option is set to true
• DEPLOY_AZURE_COSMOSDB deploys Azure CosmosDB and configures workload identity if that option is set to true. This setting will also take into account the AZURE_COSMOSDB_ACCOUNT_KIND parameter which is used to determine database API (either MongoDB or GlobalDocumentDB with MongoDB being the default)
• DEPLOY_OBSERVABILITY_TOOLS deploys Azure Log Analytics workspace, Azure Monitor managed service for Promethues, Azure Managed Grafana, and enables monitoring on the AKS cluster with Container Insights

The only services that will be deployed by default at all times will be the AKS cluster and Azure Key Vault (with Secret Store CSI driver enabled on AKS)