Show ActivityPub comments and allow replying in-app (`podcast:socialInteract` tag)

### Checklist

- [x] I have used the search function for [**OPEN**](https://github.com/AntennaPod/AntennaPod/issues) issues to see if someone else has already submitted the same feature request.
- [x] I have **also** used the search function for [**CLOSED**](https://github.com/AntennaPod/AntennaPod/issues?q=is%3Aissue+is%3Aclosed) issues to see if the feature was already implemented and is just waiting to be released, or if the feature was rejected.
- [x] I will describe the problem with as much detail as possible.
- [x] This request contains only one single feature, **not** a list of multiple (related) features.

### App version

3.7.0

### Feature or improvement you want

| ℹ️ | **Implementation instructions**|
|---|:---|
| | This request has been discussed further below. If you're interested in implementing this, please see the [conclusions relevant for implementation below](https://github.com/AntennaPod/AntennaPod/issues/7698#issuecomment-4209521965).
_{The original post has been edited by the project maintainers to add this link.} |

Following up on #7078, for those podcasts that support it, I would love to be able to
* not just open a webpage with others' comments on episodes but view them directly in-app ('phase 2'), ideally with the possibility to quickly open the conversation or initiate a reply in a Fediverse app I already have installed
* contribute to the conversation with my existing Fediverse account directly from within AntennaPod ('phase 3')

### Why should this be added?

* It helps podcasters engage their audience and create a community
* It adds a USP to AntennaPod
* As a user, I can directly see what others thought of the episode and discover more (e.g. tools for the problem that's been discussed, different perspectives for the news that was covered, additional podcasts covering the theme, etc)

### Screenshots / Drawings / Technical details

https://podcasting2.org/podcast-namespace/tags/socialInteract