Add helpers to log a GitHub "notice" (#2975)

Co-authored-by: Mike Harder <mharder@microsoft.com>

eng/common/scripts/logging.ps1

@@ -10,6 +10,26 @@ function LogInfo {
   Write-Host "$args"
 }
 
+function LogNotice {
+  if (Test-SupportsGitHubLogging) {
+    Write-Host ("::notice::$args" -replace "`n", "%0D%0A")
+  }
+  else {
+    # No equivalent for DevOps
+    Write-Host "[Notice] $args"
+  }
+}
+
+function LogNoticeForFile($file, $noticeString) {
+  if (Test-SupportsGitHubLogging) {
+    Write-Host ("::notice file=$file,line=1,col=1::$noticeString" -replace "`n", "%0D%0A")
+  }
+  else {
+    # No equivalent for DevOps
+    Write-Host "[Notice in file $file] $noticeString"
+  }
+}
+
 function LogWarning {
   if (Test-SupportsDevOpsLogging) {
     Write-Host ("##vso[task.LogIssue type=warning;]$args" -replace "`n", "%0D%0A")