Integrate PHPickerViewController in Story Editor

[kean]

Changes:

• Integrate PHPickerViewController in Story Editor
• No permission prompts are needed anymore. The only downside is that the "Add Photo" button will no longer be able to display a tiny preview of your latest photo from the gallery.
• Removes "Site Media" as a source (nobody using it; not worth re-implementing)
• Set standard maximum export resolution for images to 2048x2048 regardless of the device from which the story is created

There should be no other functional changes.
The goal is to decommission WPMediaPicker in this release.

To test:

🟡 This feature requires access to the camera and doesn’t seem to work in the simulator, even when selecting photos from the local library. I haven’t looked into it. Please test on the physical device.

To create a story, tap the "Create" button on the Home Screen and select "Story Post". Alternatively, add a "Story" block to an existing post.

• Verify that videos and images can be selected
• Verify that “Cancel” works
• Verify that the Editor no longer requires the permissions or asks for the permissions to access Photos (best tested using a clean build)
• Verify that adding photos works
• Verify that uploading both portrait and horizontal video works
• Verify that video longer than 5 minutes can’t be uploaded to free blogs
• Verify that errors are shown (hardcode in unc picker(_ picker: PHPickerViewController, didFinishPicking results: [PHPickerResult])
• Verify that the story can be uploaded

Regression Notes

1. Potential unintended areas of impact

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.

UI Changes testing checklist:

• 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 WordPress Alpha by scanning the QR code below to install the corresponding build.

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr22059-fb0f2ef
	Version	23.7
	Bundle ID	org.wordpress.alpha
	Commit	fb0f2ef
	App Center Build	WPiOS - One-Offs #7885

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

[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	pr22059-fb0f2ef
	Version	23.7
	Bundle ID	com.jetpack.alpha
	Commit	fb0f2ef
	App Center Build	jetpack-installable-builds #6909

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

[momo-ozawa]

Works as described!

[momo-ozawa]

The first time you access the stories editor on a fresh install, you see the above. I thought the button title was a bit strange. This isn't within the scope of this PR (in fact, it's defined in Kanvas), but just noting it down

[peril-wordpress-mobile]

	Warnings
⚠️	PR has more than 500 lines of code changing. Consider splitting into smaller PRs if possible.

Generated by 🚫 dangerJS

[wpmobilebot]

	1 Warning
⚠️	This PR is larger than 500 lines of changes. Please consider splitting it into smaller PRs for easier and faster reviews.

Generated by 🚫 Danger