Add JS MapTool.player functions

The interfaces return player names and take a player by name
rather than having Player proxy objects
because role checks could be confused by a player disconnecting and
rejoining with a different role.

A proxy object would need to listen to player connect/disconnect events
to keep its underlying player object in sync
and unless this proves to be a performance problem we can look up the
player by name each time.

src/main/java/net/rptools/maptool/client/script/javascript/api/JSAPIMapTool.java

@@ -30,6 +30,8 @@ public String serializeToString() {
 
   @HostAccess.Export public final JSAPINetwork network = new JSAPINetwork();
 
+  @HostAccess.Export public final JSAPIPlayer player = new JSAPIPlayer();
+
   @HostAccess.Export public final JSAPIServerInfo serverInfo = new JSAPIServerInfo();
 
   @HostAccess.Export public final JSAPITokens tokens = new JSAPITokens();

src/main/java/net/rptools/maptool/client/script/javascript/api/JSAPIPlayer.java

@@ -0,0 +1,93 @@
+/*
+ * This software Copyright by the RPTools.net development team, and
+ * licensed under the Affero GPL Version 3 or, at your option, any later
+ * version.
+ *
+ * MapTool Source Code is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License * along with this source Code.  If not, please visit
+ * <http://www.gnu.org/licenses/> and specifically the Affero license
+ * text at <http://www.gnu.org/licenses/agpl.html>.
+ */
+package net.rptools.maptool.client.script.javascript.api;
+
+import java.util.*;
+import java.util.stream.Collectors;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import net.rptools.maptool.client.MapTool;
+import net.rptools.maptool.model.player.Player;
+import org.graalvm.polyglot.HostAccess;
+
+public class JSAPIPlayer implements MapToolJSAPIInterface {
+  @Override
+  public String serializeToString() {
+    return "MapTool.player";
+  }
+
+  @HostAccess.Export
+  @Nonnull
+  public String getLocalPlayerName() {
+    return MapTool.getPlayer().getName();
+  }
+
+  @HostAccess.Export
+  @Nonnull
+  public List<String> getConnectedPlayerNames() {
+    return MapTool.getPlayerList().stream()
+        .map(player -> player.getName())
+        .collect(Collectors.toList());
+  }
+
+  @Nullable
+  private Player findPlayerByName(@Nonnull String playerName) {
+    Player player = null;
+    for (var p : MapTool.getPlayerList()) {
+      if (p.getName().equalsIgnoreCase(playerName)) {
+        player = p;
+      }
+    }
+    return player;
+  }
+
+  /**
+   * Get whether the named player is connected.
+   *
+   * @return true if the player is connected, false if not.
+   */
+  @HostAccess.Export
+  public boolean isConnected(@Nonnull String playerName) {
+    return findPlayerByName(playerName) != null;
+  }
+
+  /**
+   * Get whether the named player is a Player.
+   *
+   * @return true if the player is connected and is a Player, false otherwise.
+   */
+  @HostAccess.Export
+  public boolean isPlayer(@Nonnull String playerName) {
+    var player = findPlayerByName(playerName);
+    if (player == null) {
+      return false;
+    }
+    return player.getRole() == Player.Role.PLAYER;
+  }
+
+  /**
+   * Get whether the named player is a GM.
+   *
+   * @return true if the player is connected and is a GM, false otherwise.
+   */
+  @HostAccess.Export
+  public boolean isGM(@Nonnull String playerName) {
+    var player = findPlayerByName(playerName);
+    if (player == null) {
+      return false;
+    }
+    return player.isGM();
+  }
+}