[Notifications Refresh] Introduce likes and subscribers details share button

[justtwago]

Fixes https://github.com/Automattic/wordpress-mobile/issues/18

This PR introduces a footer with a share button for likes and subscribers notification details screens.

Subscribers	Comment Likes	Post Likes

To test:

• Prepare three types of notifications: comment likes, post likes, and subscribers
• Run the app and go to each notification and confirm all of them have a share button on the bottom of the screen
• Ensure that the share button works properly by sharing a link with either a post, comment, or blog according to the notification type.

Regression Notes

1. Potential unintended areas of impact
   Likes, Subscribers notification details screen

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

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

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

	App Name	WordPress Alpha
	Configuration	Release-Alpha
	Build Number	pr23292-ffe4c9b
	Version	24.8
	Bundle ID	org.wordpress.alpha
	Commit	ffe4c9b
	App Center Build	WPiOS - One-Offs #10064

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	pr23292-ffe4c9b
	Version	24.8
	Bundle ID	com.jetpack.alpha
	Commit	ffe4c9b
	App Center Build	jetpack-installable-builds #9113

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

[salimbraksa]

LGTM! 🚀