Starter Azure Policy for APIM when deploying the construction set

[cykreng]

From Enterprise-Scale-APIM created by cykreng: cykreng/Enterprise-Scale-APIM#27

For instance, customers can use Get-AzPolicyAlias -NamespaceMatch 'ApiManagement' to get a list of Azure Policy aliases supported by APIM to create custom Azure policies for APIM. Ideally, we should create a custom set of policies to recommend to customers when deploying the LZ as a starting point...