Optimize driver download by checking for existing WIM files

Refactors the driver download logic for all manufacturers to first check for the existence of a final `.wim` archive. If a WIM file is found, the download and processing for that model is skipped, significantly improving performance on subsequent runs.

This change also resolves a potential type conversion error when processing driver mapping JSON files and corrects a minor typo in a log message.

FFUDevelopment/FFU.Common/FFU.Common.Drivers.psm1

@@ -116,7 +116,10 @@ function Update-DriverMappingJson {
             $existingJson = Get-Content -Path $mappingFilePath -Raw | ConvertFrom-Json
             # Ensure it's a collection before adding to the list
             if ($existingJson -is [array]) {
-                $mappingList.AddRange($existingJson)
+                # Iterate through the array to avoid type conversion issues with AddRange
+                foreach ($item in $existingJson) {
+                    $mappingList.Add($item)
+                }
             }
             else {
                 $mappingList.Add($existingJson)