ability to carve vnet address space into multiple size subnets with the new cidrSubnet feature.

It would be nice to have the ability to carve up a vnet to multiple different subnets of multiple sizes.

This can be very useful for example with AKS, I can then have one subnet with a small cidr for my internal load balancers.
Another for my pod's (a big one).
Then one for something like private endpoints and another for application gateway.

Each one will never be the same cidr.

here is an example of a small clsuters with different subnets.

```bicep
// AKS vNet
@description('The details needed for the AKS vNet. Configure to your needs.')
var AKSVNetConfiguration = {
name: 'vnet-aks-${customerName}-${environmentName}-${locationshortcode}'
test: {
VNetAddressPrefixes: [
'10.240.0.0/16'
]
Subnets: [
{
name: 'clusterresources'
addressPrefix: '10.240.0.0/20'
natGatewayId: NatGateway.outputs.resourceId
}
{
name: 'clusterroles'
addressPrefix: '10.240.16.16/28'
}
]
}
dev: {
}
prod: {}
}
```

Hope that makes sense

Review the existing cidrSubnet feature and the Bicep configuration example in this issue, focusing on how multiple subnet sizes would be expressed within an Azure VNet. Define the supported input and output behavior, including the AKS scenarios described, and add coverage demonstrating that differently sized, non-overlapping subnets can be carved from one address space.

Written by the indexing model from the issue text.