Paper QOL improvements (#32418)

* Don't add newlines (fixes #32357)

* Improve UI around max paper length (Fixes #32344)

* Display a "fill progress" indicator so users know how close they are to filling it
* Don't allow users to save a paper which went over the limit, to avoid them losing data they want to keep.

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Co-authored-by: Eoin Mcloughlin <helloworld@eoinrul.es>

Content.Shared/Paper/PaperSystem.cs

@@ -201,7 +201,7 @@ public sealed class PaperSystem : EntitySystem
 
     public void SetContent(Entity<PaperComponent> entity, string content)
     {
-        entity.Comp.Content = content + '\n';
+        entity.Comp.Content = content;
         Dirty(entity);
         UpdateUserInterface(entity);