Autogenerate new object IDs for az sentinel create commands

**Is your feature request related to a problem? Please describe.**
The `az sentinel data connector create`, `az sentinel alert-rule create`, `az sentinel boomark create`, `az sentinel incident create`, and `az sentinel incident-comment create` commands all require the user to supply an ID to use for the new objects.

**Describe the solution you'd like**
It might be more convenient and intuitive for the user if the IDs for the new sentinel objects were created automatically by the system, like in the Microsoft Sentinel portal. Having to generate and enter a new ID is an extra step that isn't required by the portal. For example, when the user enters the CLI command `az sentinel data-connector create --office-data-connector --data-connector-id "{id}" ...`, they must provide a data connector ID. However, an data connector ID isn't required for the equivalent operation in the portal.