Fix Fabric transfer transaction usage (fixes #4486)

- access simulated extract operations in transaction as well
- get rid of the inner transaction, as commit or rollback depends on the spark type and thus is identical for all accesses within the outer transaction (as recommended in #4403)
- ensure to commit the outer transaction after iterating over the slots if extracting via non-creative spark

Fabric/src/main/java/vazkii/botania/fabric/integration/corporea/FabricTransferCorporeaNode.java

@@ -36,7 +36,7 @@ public List<ItemStack> extractItems(CorporeaRequest request) {
 	protected List<ItemStack> iterateOverSlots(CorporeaRequest request, boolean doit) {
 		ImmutableList.Builder<ItemStack> builder = ImmutableList.builder();
 
-		try (Transaction outer = Transaction.openOuter()) {
+		try (Transaction trans = Transaction.openOuter()) {
 			for (var storageView : inv) {
 				if (storageView.isResourceBlank()) {
 					continue;
@@ -53,21 +53,19 @@ protected List<ItemStack> iterateOverSlots(CorporeaRequest request, boolean doit
 						request.trackSatisfied(rem);
 
 						if (doit) {
-							try (Transaction trans = Transaction.openNested(outer)) {
-								builder.addAll(breakDownBigStack(item.toStack((int) inv.extract(item, rem, trans))));
-								if (!getSpark().isCreative()) {
-									// only commit if non-creative
-									trans.commit();
-								}
-							}
+							builder.addAll(breakDownBigStack(item.toStack((int) inv.extract(item, rem, trans))));
 							getSpark().onItemExtracted(stack);
 							request.trackExtracted(rem);
 						} else {
-							builder.add(item.toStack((int) inv.simulateExtract(item, rem, null)));
+							builder.add(item.toStack((int) inv.simulateExtract(item, rem, trans)));
 						}
 					}
 				}
 			}
+			if (doit && !getSpark().isCreative()) {
+				// only persist changes for non-creative sparks
+				trans.commit();
+			}
 		}
 
 		return builder.build();