feat(fax): Fax machines print, copy, and send paper labels (#25979)

* feat(fax): Client fax file-print parses and stores label

* feat(fax): Fax machines print, copy, and send paper labels

* style(Fax): Comments and formatting

* feat(fax): Make fax admin logging more consistent and clear

* refactor(fax): Replace ternary with a simpler null coalescing

* refactor(fax): Make FaxSystem Send method signature consistent with Copy, PrintFile

* refactor(fax): Read entire file and process later instead of peeking first

* refactor(fax): Remove local variables only used for style

* style(fax): Fix some nearby style errors

* fix(fax): Undo an inaccurate change to admin log formatting

* refactor(fax): Separate `firstLine` variable

* fix(fax): Use Environment.NewLine

* bienvenidos

---------

Co-authored-by: metalgearsloth <comedian_vs_clown@hotmail.com>

Content.Client/Fax/UI/FaxBoundUi.cs

@@ -40,7 +40,7 @@ public sealed class FaxBoundUi : BoundUserInterface
     {
         if (_dialogIsOpen)
             return;
-            
+
         _dialogIsOpen = true;
         var filters = new FileDialogFilters(new FileDialogFilters.Group("txt"));
         await using var file = await _fileDialogManager.OpenFile(filters);
@@ -52,8 +52,27 @@ public sealed class FaxBoundUi : BoundUserInterface
         }
 
         using var reader = new StreamReader(file);
+
+        var firstLine = await reader.ReadLineAsync();
+        string? label = null;
         var content = await reader.ReadToEndAsync();
-        SendMessage(new FaxFileMessage(content[..Math.Min(content.Length, FaxFileMessageValidation.MaxContentSize)], _window.OfficePaper));
+
+        if (firstLine is { })
+        {
+            if (firstLine.StartsWith('#'))
+            {
+                label = firstLine[1..].Trim();
+            }
+            else
+            {
+                content = firstLine + "\n" + content;
+            }
+        }
+
+        SendMessage(new FaxFileMessage(
+            label?[..Math.Min(label.Length, FaxFileMessageValidation.MaxLabelSize)],
+            content[..Math.Min(content.Length, FaxFileMessageValidation.MaxContentSize)],
+            _window.OfficePaper));
     }
 
     private void OnSendButtonPressed()