Added ability to edit message with message builder

javacord-api/src/main/java/org/javacord/api/entity/message/MessageUpdater.java

@@ -0,0 +1,42 @@
+package org.javacord.api.entity.message;
+
+import java.util.concurrent.CompletableFuture;
+
+public class MessageUpdater extends MessageBuilderBase<MessageUpdater> {
+    /**
+     * The message to update.
+     */
+    private final Message message;
+
+    /**
+     * Class constructor.
+     *
+     * @param m The message to update.
+     */
+    public MessageUpdater(Message m) {
+        super(MessageUpdater.class);
+        delegate.copy(m);
+        this.message = m;
+    }
+
+    /**
+     * Edits the message, updating all fields that have been changed by a method call.
+     * For example, the content of the message will only be patched if you called a method on this updater
+     * that affects the content.
+     *
+     * @return The edited message.
+     */
+    public CompletableFuture<Message> applyChanges() {
+        return delegate.edit(message, true);
+    }
+
+    /**
+     * Edits the message, updating all fields.
+     * Fields that have not been set will be dropped and removed from the actual message on Discord.
+     *
+     * @return The edited message.
+     */
+    public CompletableFuture<Message> replaceMessage() {
+        return delegate.edit(message, false);
+    }
+}

javacord-api/src/main/java/org/javacord/api/entity/message/internal/InteractionMessageBuilderDelegate.java

@@ -7,7 +7,7 @@
 import java.util.EnumSet;
 import java.util.concurrent.CompletableFuture;
 
-public interface InteractionMessageBuilderDelegate extends MessageBuilderDelegate {
+public interface InteractionMessageBuilderDelegate extends MessageBuilderBaseDelegate {
 
     /**
      * Sets the message flags of the message.

javacord-api/src/main/java/org/javacord/api/entity/message/internal/MessageBuilderDelegate.java → javacord-api/src/main/java/org/javacord/api/entity/message/internal/MessageBuilderBaseDelegate.java

@@ -25,7 +25,7 @@
  * This class is internally used by the {@link MessageBuilder} to create messages.
  * You usually don't want to interact with this object.
  */
-public interface MessageBuilderDelegate {
+public interface MessageBuilderBaseDelegate {
 
     /**
      * Add high-level components to the message.
@@ -350,6 +350,15 @@ public interface MessageBuilderDelegate {
      */
     CompletableFuture<Message> send(Messageable messageable);
 
+    /**
+     * Edits the message.
+     *
+     * @param message The message to edit.
+     * @param onlyChangedFields True if only changed fields should be updated
+     * @return The edited message.
+     */
+    CompletableFuture<Message> edit(Message message, boolean onlyChangedFields);
+
     /**
      * Sends the message.
      *

javacord-api/src/main/java/org/javacord/api/entity/message/internal/WebhookMessageBuilderDelegate.java

@@ -15,7 +15,7 @@
  * This class is internally used by the {@link WebhookMessageBuilder} to create messages.
  * You usually don't want to interact with this object.
  */
-public interface WebhookMessageBuilderDelegate extends MessageBuilderDelegate {
+public interface WebhookMessageBuilderDelegate extends MessageBuilderBaseDelegate {
 
     /**
      * Sets the display name of the webhook.

javacord-api/src/main/java/org/javacord/api/util/internal/DelegateFactory.java

@@ -22,7 +22,7 @@
 import org.javacord.api.entity.message.component.internal.SelectMenuOptionBuilderDelegate;
 import org.javacord.api.entity.message.embed.internal.EmbedBuilderDelegate;
 import org.javacord.api.entity.message.internal.InteractionMessageBuilderDelegate;
-import org.javacord.api.entity.message.internal.MessageBuilderDelegate;
+import org.javacord.api.entity.message.internal.MessageBuilderBaseDelegate;
 import org.javacord.api.entity.message.internal.WebhookMessageBuilderDelegate;
 import org.javacord.api.entity.message.mention.internal.AllowedMentionsBuilderDelegate;
 import org.javacord.api.entity.permission.Permissions;
@@ -157,11 +157,11 @@ public static AllowedMentionsBuilderDelegate createAllowedMentionsBuilderDelegat
     }
 
     /**
-     * Creates a new message builder delegate.
+     * Creates a new message builder base delegate.
      *
-     * @return A new message builder delegate.
+     * @return A new message builder base delegate.
      */
-    public static MessageBuilderDelegate createMessageBuilderDelegate() {
+    public static MessageBuilderBaseDelegate createMessageBuilderBaseDelegate() {
         return delegateFactoryDelegate.createMessageBuilderDelegate();
     }
 

javacord-api/src/main/java/org/javacord/api/util/internal/DelegateFactoryDelegate.java

@@ -22,7 +22,7 @@
 import org.javacord.api.entity.message.component.internal.SelectMenuOptionBuilderDelegate;
 import org.javacord.api.entity.message.embed.internal.EmbedBuilderDelegate;
 import org.javacord.api.entity.message.internal.InteractionMessageBuilderDelegate;
-import org.javacord.api.entity.message.internal.MessageBuilderDelegate;
+import org.javacord.api.entity.message.internal.MessageBuilderBaseDelegate;
 import org.javacord.api.entity.message.internal.WebhookMessageBuilderDelegate;
 import org.javacord.api.entity.message.mention.internal.AllowedMentionsBuilderDelegate;
 import org.javacord.api.entity.permission.Permissions;
@@ -80,7 +80,7 @@ public interface DelegateFactoryDelegate {
      *
      * @return A new message builder delegate.
      */
-    MessageBuilderDelegate createMessageBuilderDelegate();
+    MessageBuilderBaseDelegate createMessageBuilderDelegate();
 
     /**
      * Creates a new interaction message builder delegate.

javacord-core/src/main/java/org/javacord/core/entity/message/InteractionMessageBuilderDelegateImpl.java

@@ -20,7 +20,7 @@
 import java.util.NoSuchElementException;
 import java.util.concurrent.CompletableFuture;
 
-public class InteractionMessageBuilderDelegateImpl extends MessageBuilderDelegateImpl
+public class InteractionMessageBuilderDelegateImpl extends MessageBuilderBaseDelegateImpl
         implements InteractionMessageBuilderDelegate {
 
     /**