rl-client: implement our pf4j plugins, extract pf4j out of net.runelite package. (#2883)

runelite-client/src/main/java/com/openosrs/client/ui/JMultilineLabel.java

@@ -0,0 +1,27 @@
+package com.openosrs.client.ui;
+
+import javax.swing.JLabel;
+import javax.swing.JTextArea;
+import javax.swing.border.EmptyBorder;
+import javax.swing.text.DefaultCaret;
+
+public class JMultilineLabel extends JTextArea
+{
+	private static final long serialVersionUID = 1L;
+
+	public JMultilineLabel()
+	{
+		super();
+		setEditable(false);
+		setCursor(null);
+		setOpaque(false);
+		setFocusable(false);
+		setWrapStyleWord(true);
+		setLineWrap(true);
+		setBorder(new EmptyBorder(0, 8, 0, 8));
+		setAlignmentY(JLabel.CENTER_ALIGNMENT);
+
+		DefaultCaret caret = (DefaultCaret) getCaret();
+		caret.setUpdatePolicy(DefaultCaret.NEVER_UPDATE);
+	}
+}