chore: minor changes

- null check get tile in ThreadUnsafeCharBlocks
 - 0 to reserved ID

worldedit-bukkit/adapters/adapter-1_17_1/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_17_R1_2/PaperweightGetBlocks.java

@@ -415,7 +415,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-bukkit/adapters/adapter-1_18_2/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_18_R2/PaperweightGetBlocks.java

@@ -408,7 +408,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-bukkit/adapters/adapter-1_19/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R1/PaperweightGetBlocks.java

@@ -406,7 +406,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-bukkit/adapters/adapter-1_19_3/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R2/PaperweightGetBlocks.java

@@ -408,7 +408,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-bukkit/adapters/adapter-1_19_4/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_19_R3/PaperweightGetBlocks.java

@@ -408,7 +408,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-bukkit/adapters/adapter-1_20/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/fawe/v1_20_R1/PaperweightGetBlocks.java

@@ -386,7 +386,7 @@ public class PaperweightGetBlocks extends CharGetBlocks implements BukkitGetBloc
                     }
 
                     int ordinal = set.getBlock(lx, ly, lz).getOrdinal();
-                    if (ordinal != 0) {
+                    if (ordinal != BlockTypesCache.ReservedIDs.__RESERVED__) {
                         BlockEntity tile = entry.getValue();
                         if (PaperLib.isPaper() && tile instanceof BeaconBlockEntity) {
                             if (beacons == null) {

worldedit-core/src/main/java/com/fastasyncworldedit/core/history/changeset/SimpleChangeSetSummary.java

@@ -50,7 +50,7 @@ public class SimpleChangeSetSummary implements ChangeSetSummary {
     public Map<BlockState, Integer> getBlocks() {
         HashMap<BlockState, Integer> map = new HashMap<>();
         for (int i = 0; i < blocks.length; i++) {
-            if (blocks[i] != 0) {
+            if (blocks[i] != BlockTypesCache.ReservedIDs.__RESERVED__) {
                 BlockState state = BlockTypesCache.states[i];
                 map.put(state, blocks[i]);
             }

worldedit-core/src/main/java/com/fastasyncworldedit/core/queue/implementation/blocks/ThreadUnsafeCharBlocks.java

@@ -122,7 +122,7 @@ public class ThreadUnsafeCharBlocks implements IChunkSet, IBlocks {
 
     @Override
     public CompoundTag getTile(int x, int y, int z) {
-        return tiles.get(x, y, z);
+        return tiles == null ? null : tiles.get(x, y, z);
     }
 
     @Override