Add optional workaround for >Y128 Nether building (#615)

* Add optional workaround for >Y128 Nether building

This commit adds a config option for building above the Nether by changing the Nether's dimension ID to match the End's.

* Only check for workaround application once

* Fix mappings?

* Include a bit more for the above bedrock nether building config option

Co-authored-by: Redned <redned235@gmail.com>

bootstrap/bungeecord/src/main/java/org/geysermc/platform/bungeecord/GeyserBungeeConfiguration.java

@@ -130,6 +130,11 @@ public class GeyserBungeeConfiguration implements GeyserConfiguration {
         return config.getBoolean("cache-chunks", false);
     }
 
+    @Override
+    public boolean isAboveBedrockNetherBuilding() {
+        return config.getBoolean("above-bedrock-nether-building", false);
+    }
+
     @Override
     public BungeeMetricsInfo getMetrics() {
         return metricsInfo;