`objectReplicationPolicies` metrics return empty due to hardcoded `/default` sub-resource path

[Shuricky]

Problem

The exporter cannot fetch metrics for Microsoft.Storage/storageAccounts/objectReplicationPolicies because insights.go hardcodes /default as the sub-resource name for all storage account metric namespaces.

When metric_namespace starts with microsoft.storage/storageaccounts/, the exporter appends /<subResourceType>/default to the resource URI:

https://github.com/webdevops/azure-metrics-exporter/blob/8701afc2b013/metrics/insights.go#L74-L79

if strings.HasPrefix(strings.ToLower(p.settings.MetricNamespace), "microsoft.storage/storageaccounts/") {
    splitNamespace := strings.Split(p.settings.MetricNamespace, "/")
    // Storage accounts have an extra requirement that their ResourceURI include <type>/default
    storageAccountType := splitNamespace[len(splitNamespace)-1]
    resourceURI = resourceURI + fmt.Sprintf("/%s/default", storageAccountType)
}

This works for singleton sub-resources like blobServices/default, queueServices/default, tableServices/default, and fileServices/default, but objectReplicationPolicies sub-resources are identified by a specific
policy ID (e.g., objectReplicationPolicies/a1b2c3d4-...), not default.

The exporter ends up calling:
GET .../storageAccounts/<name>/objectReplicationPolicies/default/providers/Microsoft.Insights/metrics

When the correct URI would be:
GET .../storageAccounts/<name>/objectReplicationPolicies/<policyId>/providers/Microsoft.Insights/metrics

Azure Monitor returns an empty response with no error, so this fails silently.

Steps to Reproduce

Configure the exporter with:

  resourceType: "Microsoft.Storage/storageAccounts"
  metricNamespace: "Microsoft.Storage/storageAccounts/objectReplicationPolicies"
  metric:
    - PendingBytesForReplication
    - PendingOperationsForReplication
  aggregation:
    - average

The exporter produces zero azure_microsoft_storage_* metrics even when the storage accounts in the subscription have active object replication policies.

Expected Behavior

The exporter should be able to discover and query metrics for objectReplicationPolicies sub-resources that are not named default.