Create Azure adapter: NetworkPrivateLinkService (#4538)

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## Summary

This PR adds a new Azure adapter for Private Link Services
(`NetworkPrivateLinkService`). The adapter discovers Azure Private Link
Service resources and creates linked item queries to related resources.

## Changes

### New Files
- `sources/azure/clients/private-link-services-client.go` - Client
interface for Azure Private Link Services
- `sources/azure/shared/mocks/mock_private_link_services_client.go` -
Generated mock for testing
- `sources/azure/manual/network-private-link-service.go` - Adapter
implementation
- `sources/azure/manual/network-private-link-service_test.go` - Unit
tests
- `sources/azure/integration-tests/network-private-link-service_test.go`
- Integration tests

### Modified Files
- `sources/azure/manual/adapters.go` - Registration of the new adapter

## Linked Items

The adapter creates linked item queries to the following resource types:

| Linked Resource Type | Source Field | Method |
| --- | --- | --- |
| NetworkSubnet | IPConfigurations[].Properties.Subnet | GET |
| NetworkVirtualNetwork | (parent of subnet) | GET |
| NetworkLoadBalancerFrontendIPConfiguration |
LoadBalancerFrontendIPConfigurations | GET |
| NetworkLoadBalancer | (parent of frontend IP config) | GET |
| NetworkNetworkInterface | NetworkInterfaces | GET |
| NetworkPrivateEndpoint | PrivateEndpointConnections[].PrivateEndpoint
| GET |
| ExtendedLocationCustomLocation | ExtendedLocation.Name (when
customLocations) | GET |
| stdlib.NetworkIP | IPConfigurations[].Properties.PrivateIPAddress,
DestinationIPAddress | GET |
| stdlib.NetworkDNS | Fqdns, Alias | SEARCH |

## Health Status Mapping

Maps `ProvisioningState` to SDP health:
- `Succeeded` → HEALTH_OK
- `Creating`, `Updating`, `Deleting` → HEALTH_PENDING
- `Failed`, `Canceled` → HEALTH_ERROR
- Default → HEALTH_UNKNOWN

## Self-Review Checklist

- [x] **IAMPermissions**: Present, references
`Microsoft.Network/privateLinkServices/read`
- [x] **PredefinedRole**: Present, uses `Network Contributor`
- [x] **LinkedItemQueries**: 9 link types verified (Subnet,
VirtualNetwork, LoadBalancerFrontendIPConfiguration, LoadBalancer,
NetworkInterface, PrivateEndpoint, ExtendedLocationCustomLocation, IP,
DNS). DNS includes both Fqdns and Alias fields.
- [x] **PotentialLinks**: 9 types listed, matches LinkedItemQueries
- [x] **Unit tests**: All passing (Get, List, ListStream, StaticTests,
ErrorHandling, Get_EmptyName, List_WithNilName, PotentialLinks)
- [x] **Integration test**: All sub-tests passing (Setup, Run, Teardown)
against live Azure APIs

All checklist items passed. Ready for review.

## Related Issue

ENG-3552
<!-- CURSOR_AGENT_PR_BODY_END -->

Linear Issue:
[ENG-3552](https://linear.app/overmind/issue/ENG-3552/create-azure-adapter-networkprivatelinkservice)

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---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>
Co-authored-by: Lionel Wilson <Lionel-Wilson@users.noreply.github.com>
GitOrigin-RevId: 62a0ffaa26a4afd7fa103668d183fb68148d129c

Author: 2 people

sources/azure/clients/private-link-services-client.go

@@ -0,0 +1,35 @@
+package clients
+
+import (
+	"context"
+
+	"github.com/Azure/azure-sdk-for-go/sdk/resourcemanager/network/armnetwork/v9"
+)
+
+//go:generate mockgen -destination=../shared/mocks/mock_private_link_services_client.go -package=mocks -source=private-link-services-client.go
+
+// PrivateLinkServicesPager is a type alias for the generic Pager interface with private link service response type.
+type PrivateLinkServicesPager = Pager[armnetwork.PrivateLinkServicesClientListResponse]
+
+// PrivateLinkServicesClient is an interface for interacting with Azure private link services.
+type PrivateLinkServicesClient interface {
+	Get(ctx context.Context, resourceGroupName string, serviceName string) (armnetwork.PrivateLinkServicesClientGetResponse, error)
+	List(resourceGroupName string) PrivateLinkServicesPager
+}
+
+type privateLinkServicesClient struct {
+	client *armnetwork.PrivateLinkServicesClient
+}
+
+func (c *privateLinkServicesClient) Get(ctx context.Context, resourceGroupName string, serviceName string) (armnetwork.PrivateLinkServicesClientGetResponse, error) {
+	return c.client.Get(ctx, resourceGroupName, serviceName, nil)
+}
+
+func (c *privateLinkServicesClient) List(resourceGroupName string) PrivateLinkServicesPager {
+	return c.client.NewListPager(resourceGroupName, nil)
+}
+
+// NewPrivateLinkServicesClient creates a new PrivateLinkServicesClient from the Azure SDK client.
+func NewPrivateLinkServicesClient(client *armnetwork.PrivateLinkServicesClient) PrivateLinkServicesClient {
+	return &privateLinkServicesClient{client: client}
+}