Fix repeated key events not getting handled in search boxes (#1784)

GUIs are supposed to call enableRepeatEvents() from initGui() and
onGuiClosed() to properly handle repeated key events.  This change
adds the appropriate calls in GuiBase.

See the equivalent code in eg. Applied Energistics 2:
cc9b33b473/src/main/java/appeng/client/gui/implementations/GuiMEMonitorable.java (L224)
cc9b33b473/src/main/java/appeng/client/gui/implementations/GuiMEMonitorable.java (L399)

Fixes https://github.com/raoulvdberge/refinedstorage/issues/1762

src/main/java/com/raoulvdberge/refinedstorage/gui/GuiBase.java

@@ -20,6 +20,8 @@ import net.minecraftforge.fluids.FluidStack;
 import net.minecraftforge.fml.client.config.GuiCheckBox;
 import net.minecraftforge.fml.client.config.GuiUtils;
 import net.minecraftforge.items.SlotItemHandler;
+
+import org.lwjgl.input.Keyboard;
 import org.lwjgl.input.Mouse;
 
 import javax.annotation.Nonnull;
@@ -101,6 +103,8 @@ public abstract class GuiBase extends GuiContainer {
 
         initializing = true;
 
+        Keyboard.enableRepeatEvents(true);
+
         calcHeight();
 
         super.initGui();
@@ -117,6 +121,12 @@ public abstract class GuiBase extends GuiContainer {
         initializing = false;
     }
 
+    @Override
+    public void onGuiClosed() {
+        super.onGuiClosed();
+        Keyboard.enableRepeatEvents(false);
+    }
+
     protected void calcHeight() {
     }