Merged PR 1755: 3794 Investigate Proper log colors for Unicorn sync

Color-coded logging does not work because of issue in Cake (example: cake-build/cake#1633) and there is no obvious fix for it, so I've enabled "Warning/Info/Error" prefixes and removed Info/Debug entries from PS console output by default (visible when Sync.ps1 is called directly)

How it looks now on initial deploy:

![image.png](https://dev.azure.com/sitecoredst/f9b5d027-f29c-449f-826c-d7bb655b30f4/_apis/git/repositories/7a4bd0ee-c068-422b-8891-a5085900757d/pullRequests/1755/attachments/image.png)

Related work items: #3794

scripts/Unicorn/Unicorn.psm1

@@ -97,22 +97,26 @@ Function Invoke-StreamingWebRequest($Uri, $MAC, $Nonce) {
 	$responseStreamReader = new-object System.IO.StreamReader $responseStream
 
 	while(-not $responseStreamReader.EndOfStream) {
-		$line = $responseStreamReader.ReadLine()
+		$line = $responseStreamReader.ReadLine().Trim()
+        if([string]::IsNullOrEmpty($line))
+        {
+            continue
+        }
 
 		if($line.StartsWith('Error:')) {
-			Write-Host $line.Substring(7) -ForegroundColor Red
+			Write-Host $line -ForegroundColor Red
 		}
 		elseif($line.StartsWith('Warning:')) {
-			Write-Host $line.Substring(9) -ForegroundColor Yellow
-		}
-		elseif($line.StartsWith('Debug:')) {
-			Write-Host $line.Substring(7) -ForegroundColor Gray
+			Write-Host $line -ForegroundColor Yellow
 		}
 		elseif($line.StartsWith('Info:')) {
-			Write-Host $line.Substring(6) -ForegroundColor White
+			Write-Verbose $line -Verbose
+		}
+		elseif($line.StartsWith('Debug:')) {
+			Write-Verbose $line -Verbose
 		}
 		else {
-			Write-Host $line -ForegroundColor White
+			Write-Host $line
 		}
 
 		[void]$responseText.AppendLine($line)