[Shipping Labels] Show options to move selected items

[selanthiraiyan]

Closes: #15306

Description

Add a notice to move items between shipments when items are selected. Moved the instructions notice into a subview to be able to show the notices in a VStack (one below another).

Changes

• New MoveToShipmentNotice view with options to move to new shipment or existing shipments.
• Make the instructions notice into a subview of the split shipments detail screen.
• Initial logic to show or hide notices based on selection.

Steps to reproduce

1. Log in to a test store with the Woo Shipping plugin set up.
2. Create an order with multiple products and different quantities for each product.
3. Enter a valid shipping address for the order.
4. Open the order detail page.
5. Tap "Create shipping label".
6. Tap "Split shipments".
7. Validate that you see a notice with instructions to select items to split into shipments. Design - bsLNrhmi2xQZB4C0TzjmHB-fi-942_42236
8. Select items, and you should see another notice-like view that shows the count of selected items.
9. Tapping on "Move to" should show a "Menu" with options to move to existing or new shipments. These values are currently hardcoded and will be updated in a future PR.

Testing information

• Validated that instructions and selection notices are displayed as expected.

Screenshots

Video recording

Simulator.Screen.Recording.-.iPhone.16.Pro.-.2025-03-25.at.18.55.50.mp4

Screenshots

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• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

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[wpmobilebot]

📲 You can test the changes from this Pull Request in WooCommerce iOS by scanning the QR code below to install the corresponding build.

	App Name	WooCommerce iOS
	Build Number	pr15418-e0f41f4
	Version	22.0
	Bundle ID	com.automattic.alpha.woocommerce
	Commit	e0f41f4
	App Center Build	WooCommerce - Prototype Builds #13406

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[itsmeichigo]

The layout looks good to me! I left some comments regarding the choice of structures, but please feel free to merge and I can handle the changes as part of handling the moving of items.

[itsmeichigo]

I think we should use a VStack instead, because otherwise the notice would cover the scroll view when it's long enough:

[itsmeichigo]

This should be an adaptive stack instead to ensure the contents are readable when the font size is really large on a narrow device.

[itsmeichigo]

Actually I'll merge the PR now to unblock the work for #15307. Thank you!