Added new data class for list of protected players. Created new event for entities getting damaged and made it so that protected players don't take damage.

src/main/java/com/micle/loginprotection/data/ProtectedPlayers.java

@@ -0,0 +1,26 @@
+package com.micle.loginprotection.data;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+
+public class ProtectedPlayers {
+    private final List<ProtectedPlayer> protected_players = new ArrayList<>();
+
+    public ProtectedPlayers() { }
+
+    public void addPlayer(UUID player_uuid) {
+        protected_players.add(new ProtectedPlayer(player_uuid));
+    }
+
+    public ProtectedPlayer getPlayer(UUID player_uuid) {
+        ProtectedPlayer player = null;
+        for (ProtectedPlayer protected_player : protected_players) {
+            player = protected_player;
+            if (player.getPlayerUUID() == player_uuid) {
+                break;
+            }
+        }
+        return player;
+    }
+}