Add persistPlayerData for OfflinePlayer

Introduced a new method to handle data persistence and manipulation for `OfflinePlayer`. Ensures separation of logic from the existing `Player`-based method while maintaining consistent functionality.

Author: NonSwag

api/src/main/java/net/thenextlvl/perworlds/WorldGroup.java

@@ -366,7 +366,23 @@ default boolean isLoadingData(Player player) {
      *
      * @param player the player whose data is to be persisted and modified
      * @param data   a {@link Consumer} that manipulates the {@link PlayerData} object
+     * @see #persistPlayerData(OfflinePlayer, Consumer)
      */
     @Contract(mutates = "io")
     void persistPlayerData(Player player, Consumer<PlayerData> data);
+
+    /**
+     * Persists and modifies the data of the specified offline player using the provided consumer.
+     * The method allows manipulation through the consumer and ensures the updated data is saved to persistent storage.
+     * <p>
+     * Opposed to {@link #persistPlayerData(Player, Consumer)},
+     * this method does not try to resolve the player's data even if they are online.
+     *
+     * @param player the offline player whose data is to be persisted and modified
+     * @param data   a {@link Consumer} that manipulates the {@link PlayerData} object
+     * @see #persistPlayerData(Player, Consumer)
+     * @since 1.0.3
+     */
+    @Contract(mutates = "io")
+    void persistPlayerData(OfflinePlayer player, Consumer<PlayerData> data);
 }

src/main/java/net/thenextlvl/perworlds/group/PaperWorldGroup.java

@@ -474,6 +474,13 @@ public void persistPlayerData(Player player, Consumer<PlayerData> data) {
         writePlayerData(player, playerData);
     }
 
+    @Override
+    public void persistPlayerData(OfflinePlayer player, Consumer<PlayerData> data) {
+        var playerData = new PaperPlayerData(player.getUniqueId(), this);
+        data.accept(playerData);
+        writePlayerData(player, playerData);
+    }
+
     private Optional<PlayerData> readPlayerData(OfflinePlayer player, Path file) throws IOException {
         return readFile(file, file.resolveSibling(file.getFileName() + "_old"), PaperPlayerData.class)
                 .map(paperPlayerData -> paperPlayerData.finalize(player, this));