fix(core): Make node execution order configurable, and backward-compatible (#6507)

* fix(core): Make node execution order configurable, and backward-compatible

* ⚡ Also add new Merge-Node behaviour

* ⚡ Fix typo

* Fix lint issue

* update labels

* rename legacy to v0

* remove the unnecessary log

* default all new workflows to use v1 execution-order

* remove the controller changes

* clone default settings to avoid it getting modified

---------

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>

packages/nodes-base/nodes/Merge/test/node/workflow.mixed.not.forceInputNodeExecution.json

@@ -2366,7 +2366,9 @@
 		}
 	},
 	"active": false,
-	"settings": {},
+	"settings": {
+		"executionOrder": "v1"
+	},
 	"versionId": "6b37555c-fd78-4135-9c59-4912a71e18db",
 	"id": "1107",
 	"meta": {