Add support for sending custom players

src/main/java/net/raphimc/viaproxy/protocoltranslator/viaproxy/ViaProxyConfig.java

@@ -173,6 +173,14 @@ public class ViaProxyConfig {
     @Description("Custom MOTD to send when clients ping the proxy. Leave empty to use the target server's MOTD.")
     private String customMotd = "";
 
+    @Option("custom-players")
+    @Description({
+        "Custom Players to send when clients ping the proxy. Leave empty to use the target server's players.",
+        "For 1 player on a 8 player server with no sample players: 1/8",
+        "For 2 players on a 10 player server with 2 sample players: 2/10/player1/player2"
+    })
+    private String customPlayers = "";
+
     @Option("custom-favicon-path")
     @Description("Relative file path to a custom favicon to send when clients ping the proxy. Leave empty to use the target server's favicon.")
     private String customFaviconPath = "";
@@ -504,6 +512,10 @@ public void setCustomMotd(final String customMotd) {
         this.save();
     }
 
+    public String getCustomPlayers() {
+        return this.customPlayers;
+    }
+
     public String getCustomFaviconPath() {
         return this.customFaviconPath;
     }

src/main/java/net/raphimc/viaproxy/proxy/packethandler/StatusPacketHandler.java

@@ -64,6 +64,24 @@ public boolean handleP2S(Packet packet, List<ChannelFutureListener> listeners) {
                         obj.addProperty("favicon", FAVICON_BASE_64);
                     }
                 }
+                String customPlayers = ViaProxy.getConfig().getCustomPlayers();
+                if (!customPlayers.isBlank()) {
+                    String[] parts = customPlayers.split("/");
+                    JsonObject players = new JsonObject();
+                    players.addProperty("online", Integer.parseInt(parts[0]));
+                    players.addProperty("max", Integer.parseInt(parts[1]));
+                    if (parts.length > 2) {
+                        var sampleArray = new com.google.gson.JsonArray();
+                        for (int i = 2; i < parts.length; i++) {
+                            JsonObject samplePlayer = new JsonObject();
+                            samplePlayer.addProperty("name", parts[i]);
+                            samplePlayer.addProperty("id", "00000000-0000-0000-0000-000000000000");
+                            sampleArray.add(samplePlayer);
+                        }
+                        players.add("sample", sampleArray);
+                    }
+                    obj.add("players", players);
+                }                
                 statusResponsePacket.statusJson = obj.toString();
             } catch (Throwable ignored) {
             }