Add APIs to replace OfflinePlayer#getLastPlayed

Currently OfflinePlayer#getLastPlayed could more accurately be described
as "OfflinePlayer#getLastTimeTheirDataWasSaved".

The API doc says it should return the last time the server "witnessed"
the player, whilst also saying it should return the last time they
logged in. The current implementation does neither.

Given this interesting contradiction in the API documentation and the
current defacto implementation, I've elected to deprecate (with no
intent to remove) and replace it with two new methods, clearly named and
documented as to their purpose.

paper-api/src/main/java/org/bukkit/OfflinePlayer.java

@@ -223,7 +223,9 @@ public interface OfflinePlayer extends ServerOperator, AnimalTamer, Configuratio
      * UTC.
      *
      * @return Date of last log-in for this player, or 0
+     * @deprecated The API contract is ambiguous and the implementation may or may not return the correct value given this API ambiguity. It is instead recommended use {@link #getLastLogin()} or {@link #getLastSeen()} depending on your needs.
      */
+    @Deprecated
     public long getLastPlayed();
 
     /**
@@ -246,6 +248,30 @@ public interface OfflinePlayer extends ServerOperator, AnimalTamer, Configuratio
     @Nullable
     @Deprecated(since = "1.20.4")
     public Location getBedSpawnLocation();
+    // Paper start
+    /**
+     * Gets the last date and time that this player logged into the server.
+     * <p>
+     * If the player has never played before, this will return 0. Otherwise,
+     * it will be the amount of milliseconds since midnight, January 1, 1970
+     * UTC.
+     *
+     * @return last login time
+     */
+    public long getLastLogin();
+
+    /**
+     * Gets the last date and time that this player was seen on the server.
+     * <p>
+     * If the player has never played before, this will return 0. If the
+     * player is currently online, this will return the current time.
+     * Otherwise it will be the amount of milliseconds since midnight,
+     * January 1, 1970 UTC.
+     *
+     * @return last seen time
+     */
+    public long getLastSeen();
+    // Paper end
 
     /**
      * Gets the Location where the player will spawn at, null if they