feat/154: add a Podcast Platforms Block

[Sidsector9]

Closes #154

Description of the Change

This PR adds the Podcast Platforms block.

Podcasting Platforms block

Podcasting Platforms settings

Verification Process

1. Add few podcasts.
2. On the podcasts edit screen, scroll down to the Podcasting Platforms section.
3. Set few platforms on which the podcast will be available.
4. Add the Podcast Platforms block to a page and select the podcast from the search field.
5. Confirm the output on the frontend, and also validate a11y.

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Changelog Entry

Credits

Props @jeffpaul @Sidsector9

[Sidsector9]

@iamdharmesh this is ready for your review.

[iamdharmesh]

Thank you for the PR and great work here @Sidsector9. Just added 2-3 minor notes to discuss other wise all good.

Thanks

[iamdharmesh]

Nitpick:
I think keeping the icon theme option at block level is more user-friendly. Not a major issue, but love to hear your thoughts on this.

[Sidsector9]

@iamdharmesh that's a good idea, but something we can iteratively implement?

[iamdharmesh]

Sure @Sidsector9, maybe we should create a follow-up issue for this?

[iamdharmesh]

Thank you for the changes @Sidsector9, LGTM!