feat(core): Add "Sent by n8n" attribution (#7183)

Github issue / Community forum post (link here to close automatically):

---------

Co-authored-by: Giulio Andreini <g.andreini@gmail.com>

packages/workflow/src/Interfaces.ts

@@ -740,6 +740,7 @@ export interface FunctionsBase {
 	getTimezone(): string;
 	getRestApiUrl(): string;
 	getInstanceBaseUrl(): string;
+	getInstanceId(): Promise<string>;
 
 	getMode?: () => WorkflowExecuteMode;
 	getActivationMode?: () => WorkflowActivateMode;