Photos section evolution

# Photos section evolution
Because of multiple feature request (eg. #6297, #6784, #7128, #7451, #7452) on the Photos section of the android application, may I suggest to discuss about what the Photos section should be and how it should evolve ?

## Questions
For now, in addition of file management and thanks to developers, the Nextcloud Android App is also dealing with Photo/Video backup ... but what's next ?

Keeping in mind that server side Photos app is also evolving with many interesting features and features requests (eg. virtual album, face recognition, etc.) what about Photos section in the Android App :
- Future of it:
- Should it be kept as a very simple gallery display ?
- Should it be enhanced with "Google Photo" features ?
- Where:
- Should we keep enhancing the Photos section in Nextcloud android app ?
- Should we create a standalone "Nextcloud Photo" application (thinking about Nextcloud Talk) to deal with "Google Photo" alternative (backup/edit/display) ?

## My Opinion
As an end user : now that Google Photo [announced](https://blog.google/products/photos/storage-changes) that the free tiers is gonna end (2020-07-01), I'm looking for a real alternative and I really hope that nextcloud will be able to support one.

As a developer I think doing a standalone app can be a good idea:
- On the webserver side "Photos" is an activatable app (as Talk)
- Sync enhancement with server side Photos app with its own repository (thinking about a [Project](https://github.com/orgs/nextcloud/projects) referencing issues/PR with Server/Android/iOS)
- It will permit to focus and not interfere with different purposes/behaviors/features between Files and Photos
- Behavior and features may differ over time and enhancement between Files and Photos (eg: local/cloud media file management)

## Other
I created a [discussion](https://help.nextcloud.com/t/the-evolution-of-photos-section/99072) on the forum to also get feedback from end user.