[Woo POS] Use x to close POS reader modals

[joshheald]

Part of: #13731 Merge after: #13770

Description

This is part of a series of PRs to improve the card reader connnection screens. You may want to test at the end of the series, as it could get quite repetitive, but doing it all in one was quite big. Up to you! The last one is #13775

As per the new designs, this uses x to close the modals instead of a cancel button, in most cases.

I have used some judgement here – if it feels like you're taking more of an action, e.g. after a reader update fails, I've left it as a cancel button.

The cancel handler doesn't update the UI immediately – that hasn't changed, but it does feel a little strange to have to wait for it to close. I think sorting that's outside the scope of this change though.

Steps to reproduce

1. Launch the app
2. Enter the POS
3. Tap Connect your reader
4. Tap x to cancel

Using a physical reader to test error states:

1. Launch the app
2. Enter the POS
3. Tap Connect your reader
4. Turn off Bluetooth
5. Observe that an error is shown, tap x to close it

Testing information

I've tested these on an iPad running iOS 16, and run through each modal to check that the button does the same as the previous cancel button did.

No unit tests as this is UI only

Screenshots

Note that this video is from this branch – if you test later on, the rest of the modal UI will look a bit different.

https://github.com/user-attachments/assets/c1d62a92-6158-464f-ac56-406b9853c103

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• [x] 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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