Update ValidateScenario to cater for AV Set resource IDs different casing .psm1 (#146)

If the Resource ID of Availability sets are in different cases the script fails as it thinks they are different resources. This is due to the use of Get-unique being case sensitive.  The fix is to convert the resource id to lower before  running get-unique

Author: javalentine91

AzureBasicLoadBalancerUpgrade/module/AzureBasicLoadBalancerUpgrade/modules/ValidateScenario/ValidateScenario.psm1

@@ -736,7 +736,9 @@ Function Test-SupportedMultiLBScenario {
         ForEach ($config in $multiLBConfig) {
             $basicLBBackends += $config.BasicLoadBalancer.BackendAddressPools.BackendIpConfigurations.id | ForEach-Object { $_.split('/virtualMachines/')[0] }
         }
-        $groupedBackends = $basicLBBackends | Sort-Object | Get-Unique
+        
+        $groupedBackends = $basicLBBackends | ForEach-Object { $_.id.ToLower() } | Sort-Object | Get-Unique
+
 
         If ($groupedBackends.Count -gt 1) {
             log -Severity Error -Message "[Test-SupportedMultiLBScenario] The provided Basic Load Balancers do not share backend pool members (more than one backend VMSS found: '$($groupedBackends)'). Using -multiLBConfig when backend is not shared adds risk and complexity in recovery." -terminateOnError
@@ -807,4 +809,4 @@ Function Test-SupportedMultiLBScenario {
     log -Message "[Test-SupportedMultiLBScenario] Multi-LB configuration is valid for migration"
 }
 
-Export-ModuleMember -Function Test-SupportedMigrationScenario, _GetScenarioBackendType, Test-SupportedMultiLBScenario
+Export-ModuleMember -Function Test-SupportedMigrationScenario, _GetScenarioBackendType, Test-SupportedMultiLBScenario