Add base exception class MultiverseException.

Allows for localized messages to be contained in our exceptions.

src/main/java/com/onarandombox/MultiverseCore/exceptions/MultiverseException.java

@@ -0,0 +1,52 @@
+package com.onarandombox.MultiverseCore.exceptions;
+
+import com.onarandombox.MultiverseCore.commandtools.MVCommandIssuer;
+import com.onarandombox.MultiverseCore.utils.message.Message;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * A base exception for Multiverse.
+ * <br/>
+ * {@link #getMVMessage()} provides access to a {@link Message} which can be used to provide a localized message. See
+ * {@link MVCommandIssuer#sendInfo(Message)}.
+ */
+public class MultiverseException extends Exception {
+
+    private final @Nullable Message message;
+
+    /**
+     * Creates a new exception with the given message and cause.
+     * <br/>
+     * If the message is not null, this exception will also contain a {@link Message} which can be accessed via
+     * {@link #getMVMessage()}. This message will just be the given message wrapped in a {@link Message}.
+     *
+     * @param message The message for the exception
+     * @param cause The cause of the exception
+     */
+    public MultiverseException(@Nullable String message, @Nullable Throwable cause) {
+        this(message != null ? Message.of(message) : null, cause);
+    }
+
+    /**
+     * Creates a new exception with the given message and cause.
+     * <br/>
+     * If the message is not null, this exception will also contain a String message which can be accessed via
+     * {@link #getMessage()}. This message will just be the given message formatted without locale support.
+     *
+     * @param message The message for the exception
+     * @param cause The cause of the exception
+     */
+    public MultiverseException(@Nullable Message message, @Nullable Throwable cause) {
+        super(message != null ? message.formatted() : null, cause);
+        this.message = message;
+    }
+
+    /**
+     * Gets the {@link Message} for this exception.
+     *
+     * @return The message, or null if none was provided
+     */
+    public final @Nullable Message getMVMessage() {
+        return message;
+    }
+}