Require plan.command permission to execute /plan or /planproxy commands

Affects issues:
- Fixed #3526

Plan/bukkit/src/main/java/com/djrapitops/plan/commands/use/BukkitCommand.java

@@ -55,6 +55,9 @@ public class BukkitCommand implements CommandExecutor, TabCompleter {
 
     @Override
     public boolean onCommand(CommandSender sender, Command cmd, String label, String[] args) {
+        if (command.getRequiredPermissions().stream().anyMatch(permission -> !sender.hasPermission(permission))) {
+            return true;
+        }
         runnableFactory.create(() -> {
             try {
                 command.getExecutor().accept(getSender(sender), new Arguments(args));
@@ -70,6 +73,9 @@ public class BukkitCommand implements CommandExecutor, TabCompleter {
 
     @Override
     public List<String> onTabComplete(CommandSender sender, Command cmd, String label, String[] args) {
+        if (command.getRequiredPermissions().stream().anyMatch(permission -> !sender.hasPermission(permission))) {
+            return Collections.emptyList();
+        }
         try {
             return command.getArgumentResolver().apply(getSender(sender), new Arguments(args));
         } catch (Exception e) {

Plan/bungeecord/src/main/java/com/djrapitops/plan/command/use/BungeeCommand.java

@@ -19,6 +19,7 @@ package com.djrapitops.plan.command.use;
 import com.djrapitops.plan.commands.use.Arguments;
 import com.djrapitops.plan.commands.use.CMDSender;
 import com.djrapitops.plan.commands.use.Subcommand;
+import com.djrapitops.plan.settings.Permissions;
 import com.djrapitops.plan.utilities.logging.ErrorContext;
 import com.djrapitops.plan.utilities.logging.ErrorLogger;
 import net.md_5.bungee.api.CommandSender;
@@ -42,7 +43,7 @@ public class BungeeCommand extends Command implements TabExecutor {
             ErrorLogger errorLogger,
             Subcommand command, String name
     ) {
-        super(name);
+        super(name, Permissions.USE_COMMAND.getPermission());
         this.runnableFactory = runnableFactory;
         this.errorLogger = errorLogger;
 

Plan/common/src/main/java/com/djrapitops/plan/commands/PlanCommand.java

@@ -102,6 +102,7 @@ public class PlanCommand {
         CommandWithSubcommands command = CommandWithSubcommands.builder(locale)
                 .alias(commandName)
                 .colorScheme(colors)
+                .requirePermission(Permissions.USE_COMMAND.getPermission())
                 .subcommand(serverCommand())
                 .subcommand(serversCommand())
                 .subcommand(networkCommand())

Plan/common/src/main/java/com/djrapitops/plan/settings/Permissions.java

@@ -22,6 +22,7 @@ package com.djrapitops.plan.settings;
  * @author AuroraLS3
  */
 public enum Permissions {
+    USE_COMMAND("plan.command"),
     SERVER("plan.server"),
     SERVERS("plan.servers"),
     NETWORK("plan.network"),

Plan/nukkit/src/main/java/com/djrapitops/plan/PlanNukkit.java

@@ -158,6 +158,9 @@ public class PlanNukkit extends PluginBase implements PlanPlugin {
             sender = new NukkitCMDSender(actualSender);
         }
 
+        if (command.getRequiredPermissions().stream().anyMatch(permission -> !sender.hasPermission(permission))) {
+            return true;
+        }
         runnableFactory.create(() -> {
             try {
                 command.getExecutor().accept(sender, new Arguments(args));

Plan/velocity/src/main/java/com/djrapitops/plan/commands/use/VelocityCommand.java

@@ -43,6 +43,9 @@ public class VelocityCommand implements SimpleCommand {
     public void execute(final Invocation invocation) {
         CommandSource source = invocation.source();
         String[] args = invocation.arguments();
+        if (command.getRequiredPermissions().stream().anyMatch(permission -> !source.hasPermission(permission))) {
+            return;
+        }
         runnableFactory.create(() -> {
             try {
                 command.getExecutor().accept(getSender(source), new Arguments(args));
@@ -67,6 +70,9 @@ public class VelocityCommand implements SimpleCommand {
     public List<String> suggest(final Invocation invocation) {
         CommandSource source = invocation.source();
         String[] currentArgs = invocation.arguments();
+        if (command.getRequiredPermissions().stream().anyMatch(permission -> !source.hasPermission(permission))) {
+            return Collections.emptyList();
+        }
         try {
             return command.getArgumentResolver().apply(getSender(source), new Arguments(currentArgs));
         } catch (Exception e) {