feat(core): Add support for pairedItem (beta) (#3012)

* ✨ Add pairedItem support

* 👕 Fix lint issue

* 🐛 Fix resolution in frontend

* 🐛 Fix resolution issue

* 🐛 Fix resolution in frontend

* 🐛 Fix another resolution issue in frontend

* ⚡ Try to automatically add pairedItem data if possible

* ⚡ Cleanup

* ⚡ Display expression errors in editor UI

* 🐛 Fix issue that it did not display errors in production

* 🐛 Fix auto-fix of missing pairedItem data

* 🐛 Fix frontend resolution for not executed nodes

* ⚡ Fail execution on pairedItem resolve issue and display information
about itemIndex and runIndex

* ⚡ Allow that pairedItem is only set to number if runIndex is 0

* ✨ Improve Expression Errors

* ⚡ Remove no longer needed code

* ⚡ Make errors more helpful

* ⚡ Add additional errors

* 👕 Fix lint issue

* ⚡ Add pairedItem support to core nodes

* ⚡ Improve support in Merge-Node

* ⚡ Fix issue with not correctly converted incoming pairedItem data

* 🐛 Fix frontend resolve issue

* 🐛 Fix frontend parameter name display issue

* ⚡ Improve errors

* 👕 Fix lint issue

* ⚡ Improve errors

* ⚡ Make it possible to display parameter name in error messages

* ⚡ Improve error messages

* ⚡ Fix error message

* ⚡ Improve error messages

* ⚡ Add another error message

* ⚡ Simplify

packages/nodes-base/nodes/SplitInBatches/SplitInBatches.node.ts

@@ -94,6 +94,12 @@ export class SplitInBatches implements INodeType {
 			return null;
 		}
 
+		returnItems.map((item, index) => {
+			item.pairedItem = {
+				item: index,
+			};
+		});
+
 		return this.prepareOutputData(returnItems);
 	}
 }