[Compute] vm create, support network configuration in --count mode

[qwordy]

Is your feature request related to a problem? Please describe.

Support the following parameters in --count mode.

--subnet
The name of the subnet when creating a new VNet or referencing an existing one. Can also reference an existing subnet by ID. If both vnet-name and subnet are omitted, an appropriate VNet and subnet will be selected automatically, or a new one will be created.

--vnet-name
Name of the virtual network when creating a new one or referencing an existing one.

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[yonzhan]

Compute