Make search box toggle key configurable (#3650)

Fixes #3641

src/main/java/appeng/client/ActionKey.java

@@ -0,0 +1,28 @@
+
+package appeng.client;
+
+
+import org.lwjgl.input.Keyboard;
+
+
+public enum ActionKey
+{
+	TOGGLE_FOCUS( Keyboard.KEY_TAB );
+
+	private final int defaultKey;
+
+	private ActionKey( int defaultKey )
+	{
+		this.defaultKey = defaultKey;
+	}
+
+	public String getTranslationKey()
+	{
+		return "key." + this.name().toLowerCase() + ".desc";
+	}
+
+	public int getDefaultKey()
+	{
+		return this.defaultKey;
+	}
+}