`Microsoft.Network/virtualNetworks` resource missing various `required` definitions

* "properties" is not marked as required, even though it MUST be specified on a PUT
https://github.com/Azure/azure-rest-api-specs/blob/88e7838a09868a51de3894114355c75929847a46/specification/network/resource-manager/Microsoft.Network/stable/2021-02-01/virtualNetwork.json#L1851-L1855

* "location" is not marked as required, even though it's required on a PUT:
https://github.com/Azure/azure-rest-api-specs/blob/88e7838a09868a51de3894114355c75929847a46/specification/network/resource-manager/Microsoft.Network/stable/2021-02-01/network.json#L156-L159

I suspect this also applies to different `Microsoft.Network` resources, different properties, and different API versions.

First raised here: https://github.com/Azure/bicep/issues/784#issuecomment-932373032

Start with specification/network/resource-manager/Microsoft.Network/stable/2021-02-01/virtualNetwork.json and network.json at the linked definitions. Compare the PUT requirements for properties and location with their required metadata, then check whether the same omission affects other Microsoft.Network resources or API versions. Done means the applicable required definitions are accurately represented.

Written by the indexing model from the issue text.