fix: Correctly set parent flow name in GovPayMetadata

[DafyddLlyr]

What's the problem?

• The Editor interface of the Pay component only ever knows about its own context - flowName will always be the flow it's held within
• At runtime, as an applicant hits the public interface of the component, the context can be different - flowName is the root ("parent" flow)
• This means that we send the incorrect flow name to GovPay

What's the solution?

• Be a bit more smart about setting the defaults at runtime in the Public interface
• Always overwrite with the current flow name, which is always correct

Testing

I didn't find a good way to test this (without setting up a new E2E test). Open to ideas!

You can test this manually here -

• Public interface - https://3826.planx.pizza/buckinghamshire/test-pay-metadata/published?analytics=false
• Editor interface - https://3826.planx.pizza/buckinghamshire/test-pay-metadata

[DafyddLlyr]

When the name of a flow changes, the metadata value in the Pay component should also update

[github-actions]

Removed vultr server and associated DNS entries

[DafyddLlyr]

Before - defaults were only applied if nothing was set in the Editor.

Now - defaults overwrite any value set in the Editor, and are always correct and up to date.

[jessicamcinchak]

Pay-in-a-portal is definitely a new-to-me content pattern! Thanks for getting to bottom of this one, works for me ✔️