Offline Mode: Add "Discard Changes" button (RFC)

[kean]

I've been testing different terminal errors and found myself in a need to discard locally made changes. It's like a delayed variant of "Back / Discard Changes": maybe you changed your mind, maybe some media fails to upload and you want to just give up on your changes – this button allows you do do that.

Note: it wasn't in the original spec.

I can't say that I liked the location of this button. It might be worth moving it somewhere deeper in the editor (or settings?). Or not including it?

https://github.com/wordpress-mobile/WordPress-iOS/assets/1567433/ec5fa3c4-485a-4765-8d4c-6fec83dcf4b2

Regression Notes

1. Potential unintended areas of impact: Post List

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

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

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.

Testing checklist:

• [ ] WordPress.com sites and self-hosted Jetpack sites.
• [ ] Portrait and landscape orientations.
• [ ] Light and dark modes.
• [ ] Fonts: Larger, smaller and bold text.
• [ ] High contrast.
• [ ] VoiceOver.
• [ ] Languages with large words or with letters/accents not frequently used in English.
• [ ] Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• [ ] iPhone and iPad.
• [ ] Multi-tasking: Split view and Slide over. (iPad)

[wpmobilebot]

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

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr23081-a72da63
	Version	24.7
	Bundle ID	com.jetpack.alpha
	Commit	a72da6342e11a7a258b80abdef207f77734c3556
	App Center Build	jetpack-installable-builds #8693

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[wpmobilebot]

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

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr23081-a72da63
	Version	24.7
	Bundle ID	org.wordpress.alpha
	Commit	a72da6342e11a7a258b80abdef207f77734c3556
	App Center Build	WPiOS - One-Offs #9649

Automatticians: You can use our internal self-serve MC tool to give yourself access to App Center if needed.