fix(Wise Node): Use ISO formatting for timestamps

[mocanew]

Summary

Using Wise node's get many transfers functionality generates a 422 Unprocessable Entity error from the Wise API due to the date fields being formatted as 2024-07-02T15:10:15+00:00 instead of 2024-07-02T15:10:15Z. This PR fixes this issue.

Related Linear tickets, Github issues, and Community forum posts

I've not opened an issue for this. I had to solve this issue for our internally deployed n8n and wanted to contribute back.

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[netroy]

for posterity, can you please link to Wise docs that say that these timestamps need to be at UTC? 🙏🏽

[mocanew]

Here's the Wise docs link. They don't explicitly say it's UTC only, but the format yyyy-mm-ddThh:mm:ss.sssZ (for createdDateStart and createdDateEnd) implies timezone offsets are not supported.

Regardless of the timezone part, the current date format is not supported. Since this functionality has worked in the past, I suspect a Moment.js update changed the default formatting.