Feature - Add Nametag Visibility Override

[ItsNature]

Overview

Description:
Adds a per-viewer nametag visibility override to the Nametag module.

Changes:

• New NametagVisibilityOverride enum:
  • SHOWN: displays the nametag as if the target's team nametag visibility were always (still respecting invisibility).
  • HIDDEN: hides the nametag as if it were never, even when the target is not on any team.
  • NONE: keeps the vanilla behavior.
• New Nametag builder field: visibilityOverride

Code Example:

 public void overrideNametagExample(Player viewer, Player target) {
     Optional<ApolloPlayer> apolloPlayerOpt = Apollo.getPlayerManager().getPlayer(viewer.getUniqueId());

     apolloPlayerOpt.ifPresent(apolloPlayer -> {
         this.nametagModule.overrideNametag(apolloPlayer, target.getUniqueId(), Nametag.builder()
             .lines(Lists.newArrayList(
                 Component.text()
                     .content("[StaffMode]")
                     .decorate(TextDecoration.ITALIC)
                     .color(NamedTextColor.GRAY)
                     .build(),
                 Component.text()
                     .content(target.getName())
                     .color(NamedTextColor.RED)
                     .build()
             ))
+            .visibilityOverride(NametagVisibilityOverride.SHOWN)
             .build()
         );
     });
 }

---

Review Request Checklist

• Your code follows the style guidelines of this project.
• I have performed a self-review of my code.
• I have tested this change myself. (If applicable)
• I have made corresponding changes to the documentation. (If applicable)
• The branch name follows the projects naming conventions. (e.g. feature/add-module & bugfix/fix-issue)

---