[Notifications P1] Replace AsyncImage with CachedAsyncImage

[alpavanoglu]

Fixes #22642 & #22647

Description

The current implementation has no caching mechanism. This PR introduces the newly added CachedAsyncImage to AvatarsView
It also fixes the horizontal margin mismatch between rows that have indicator and rows that don't.

Testing Steps

1. Install & Login Jetpack
2. Navigate to Notifications tab
3. ✅ Verify that the replicating images are not being fetched again from network
4. ✅ Verify that the text line for each row is the same regardless of what style is the avatar and whether there's indicator or not. The trailing padding for indicator with multi-avatar views will be less than single avatar views.

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.

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)

[dangermattic]

	1 Warning
⚠️	View files have been modified, but no screenshot or video is included in the pull request. Consider adding some for clarity.

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[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	pr22643-bdbd1cf
	Version	24.3
	Bundle ID	com.jetpack.alpha
	Commit	bdbd1cf
	App Center Build	jetpack-installable-builds #7904

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

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr22643-bdbd1cf
	Version	24.3
	Bundle ID	org.wordpress.alpha
	Commit	bdbd1cf
	App Center Build	WPiOS - One-Offs #8874

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

[salimbraksa]

✅ Scrolling back to notifications doesn't reload the avatars
✅ Avatars and texts are aligned with or without the indicator

LGTM!