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.Shared/Fax/SharedFax.cs

@@ -37,11 +37,13 @@ public sealed class FaxUiState : BoundUserInterfaceState
 [Serializable, NetSerializable]
 public sealed class FaxFileMessage : BoundUserInterfaceMessage
 {
+    public string? Label;
     public string Content;
     public bool OfficePaper;
 
-    public FaxFileMessage(string content, bool officePaper)
+    public FaxFileMessage(string? label, string content, bool officePaper)
     {
+        Label = label;
         Content = content;
         OfficePaper = officePaper;
     }
@@ -49,6 +51,7 @@ public sealed class FaxFileMessage : BoundUserInterfaceMessage
 
 public static class FaxFileMessageValidation
 {
+    public const int MaxLabelSize = 50; // parity with Content.Server.Labels.Components.HandLabelerComponent.MaxLabelChars
     public const int MaxContentSize = 10000;
 }