[v10.0.x] Azure: Settings for Azure AD Workload Identity (#75686)

* Azure: Settings for Azure AD Workload Identity (#75283)

* Settings for Azure AD Workload Identity

* Update dependency on Grafana Azure SDK

* Documentation

* Fix JS code

* Cleanup Prometheus backend code

* Making prettier happy

(cherry picked from commit 3ee40d3a5a)

# Conflicts:
#	conf/defaults.ini
#	conf/sample.ini
#	docs/sources/setup-grafana/configure-grafana/_index.md
#	go.mod
#	go.sum
#	packages/grafana-runtime/src/config.ts
#	pkg/api/dtos/frontend_settings.go
#	pkg/api/frontendsettings.go
#	pkg/setting/setting_azure.go
#	public/app/plugins/datasource/mssql/azureauth/AzureAuth.testMocks.ts

* Fix build

---------

Co-authored-by: Sergey Kostrukov <sekost@microsoft.com>

pkg/setting/setting_azure.go

@@ -15,5 +15,23 @@ func (cfg *Cfg) readAzureSettings() {
 	azureSettings.ManagedIdentityEnabled = azureSection.Key("managed_identity_enabled").MustBool(false)
 	azureSettings.ManagedIdentityClientId = azureSection.Key("managed_identity_client_id").String()
 
+	// Workload Identity authentication
+	if azureSection.Key("workload_identity_enabled").MustBool(false) {
+		azureSettings.WorkloadIdentityEnabled = true
+		workloadIdentitySettings := &azsettings.WorkloadIdentitySettings{}
+
+		if val := azureSection.Key("workload_identity_tenant_id").String(); val != "" {
+			workloadIdentitySettings.TenantId = val
+		}
+		if val := azureSection.Key("workload_identity_client_id").String(); val != "" {
+			workloadIdentitySettings.ClientId = val
+		}
+		if val := azureSection.Key("workload_identity_token_file").String(); val != "" {
+			workloadIdentitySettings.TokenFile = val
+		}
+
+		azureSettings.WorkloadIdentitySettings = workloadIdentitySettings
+	}
+
 	cfg.Azure = azureSettings
 }