Blogging Prompt Compact Card: show a real prompt

[ScoutHarris]

Ref: #18429

The compact prompt card now fetches one prompt and updates the card accordingly.

To test:

• Enable bloggingPrompts feature flag.
• Tap on the FAB.
• Verify the prompt is displayed in the header.
• HACK: In BloggingPromptsHeaderView:configure, set answered to true.

    func configure(_ prompt: BloggingPrompt?) {
        promptLabel.text = prompt?.text ?? nil

//        let answered = prompt?.answered ?? false
        let answered = true
        
        answerPromptButton.isHidden = answered
        answeredStackView.isHidden = !answered
    }

• Verify the answered state on the card is toggled correctly.

Not Answered	Answered

Regression Notes

1. Potential unintended areas of impact
   N/A

2. What I did to test those areas of impact (or what existing automated tests I relied on)
   N/A

3. What automated tests I added (or what prevented me from doing so)
   N/A

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

[wpmobilebot]

You can test the changes in Jetpack from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr18572-1d169de on your iPhone

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[wpmobilebot]

You can test the changes in WordPress from this Pull Request by:

• Clicking here or scanning the QR code below to access App Center
• Then installing the build number pr18572-1d169de on your iPhone

If you need access to App Center, please ask a maintainer to add you.

[wargcm]

LGTM! Only a couple minor things.

[wargcm]

[Nitpick]: The ?? nil isn't needed here

[wargcm]

This would also end up being called on the 'Pages' screen since it uses this coordinator. It could probably be mitigated by either checking the presenting view controller or the number of actions. Or alternatively, moving the fetch to the same spot the header is created. What are your thoughts?

[ScoutHarris]

This would also end up being called on the 'Pages' screen since it uses this coordinator.

Woops. Forgot that was different.

moving the fetch to the same spot the header is created

That was my original intent. However, since everything was dependent on the fetching, it led to a blackhole of completion blocks. The intent for fetching the prompt in init is to be sure there is a prompt before it is needed.

checking the presenting view controller

This felt a bit more fragile as things could move, the FAB could be added somewhere else, etc.

the number of actions

This felt like the best dynamic option. Door #3 it is!

[ScoutHarris]

Thanks @wargcm !