feat(core): Add support for building LLM applications (#7235)

This extracts all core and editor changes from #7246 and #7137, so that
we can get these changes merged first.

ADO-1120

[DB Tests](https://github.com/n8n-io/n8n/actions/runs/6379749011)
[E2E Tests](https://github.com/n8n-io/n8n/actions/runs/6379751480)
[Workflow Tests](https://github.com/n8n-io/n8n/actions/runs/6379752828)

---------

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Oleg Ivaniv <me@olegivaniv.com>
Co-authored-by: Alex Grozav <alex@grozav.com>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

packages/editor-ui/src/components/NodeIcon.vue

@@ -42,6 +42,10 @@ export default defineComponent({
 			type: Boolean,
 			default: false,
 		},
+		colorDefault: {
+			type: String,
+			required: false,
+		},
 		showTooltip: {
 			type: Boolean,
 			default: false,
@@ -67,6 +71,9 @@ export default defineComponent({
 			if (nodeType && nodeType.defaults && nodeType.defaults.color) {
 				return nodeType.defaults.color.toString();
 			}
+			if (this.colorDefault) {
+				return this.colorDefault;
+			}
 			return '';
 		},
 		iconSource(): NodeIconSource {