Extract metadata from policy for rules generation

[BernieWhite]

When generating rules from policy lets extract additional metadata from policies for inserting into the rule definition.

An example policy definition.

{
  "Name": "a4fe33eb-e377-4efb-ab31-0784311bc499",
  "ResourceId": "/providers/Microsoft.Authorization/policyDefinitions/a4fe33eb-e377-4efb-ab31-0784311bc499",
  "ResourceName": "a4fe33eb-e377-4efb-ab31-0784311bc499",
  "ResourceType": "Microsoft.Authorization/policyDefinitions",
  "SubscriptionId": null,
  "Properties": {
    "Description": "This policy audits any Windows/Linux virtual machines (VMs) if the Log Analytics agent is not installed which Security Center uses to monitor for security vulnerabilities and threats",
    "DisplayName": "Log Analytics agent should be installed on your virtual machine for Azure Security Center monitoring",
    "Metadata": {
      "version": "1.0.0",
      "category": "Security Center"
    },
    "Mode": "All",
    "Parameters": {
      "effect": {
        "type": "String",
        "metadata": {
          "displayName": "Effect",
          "description": "Enable or disable the execution of the policy"
        },
        "allowedValues": [
          "AuditIfNotExists",
          "Disabled"
        ],
        "defaultValue": "AuditIfNotExists"
      }
    },
    "PolicyRule": {
      "if": {
        "field": "type",
        "in": [
          "Microsoft.ClassicCompute/virtualMachines",
          "Microsoft.Compute/virtualMachines"
        ]
      },
      "then": {
        "effect": "[parameters('effect')]",
        "details": {
          "type": "Microsoft.Security/assessments",
          "name": "d1db3318-01ff-16de-29eb-28b344515626",
          "existenceCondition": {
            "field": "Microsoft.Security/assessments/status.code",
            "in": [
              "NotApplicable",
              "Healthy"
            ]
          }
        }
      }
    },
    "PolicyType": 2
  },
  "PolicyDefinitionId": "/providers/Microsoft.Authorization/policyDefinitions/a4fe33eb-e377-4efb-ab31-0784311bc499"
}

Lets extract:

• Properties.metadata.version as a Azure.Policy/version annotation if it exists.
• Properties.metadata.category as a Azure.Policy/category tag if it exists.

Related to #181