Add notification icon to podcast header

[SergioEstevao]

📘 Part of: #2825

Fix #2826

In order to match Android we are adding Notification toggle to the Podcast header, before we start implementing the new header interface.

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To test

1. Start the app
2. Ensure you have tracksLogging FF enabled
3. Open a podcast detail screen for a blog that you follow
4. Check if you see a notification icon on the top header
5. Tap on the icon
6. Check if the icon change state and you see a Toast informing of the new state
7. Check also if you see in the console an event called podcast_screen_notifications_tapped in the console

Checklist

• I have considered if this change warrants user-facing release notes and have added them to CHANGELOG.md if necessary.
• I have considered adding unit tests for my changes.
• I have updated (or requested that someone edit) the spreadsheet to reflect any new or changed analytics.

[dangermattic]

	1 Warning
⚠️	This PR is assigned to the milestone 7.84 ❄️. The due date for this milestone has already passed. Please assign it to a milestone with a later deadline or check whether the release for this milestone has already been finished.

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[danielebogo]

Works as expected and I can see the events being tracked