feat(linux/vfs): integrate openvfs linux virtual files plugin

[mgallien]

Resolves

#

Summary

TODO

• ...

Checklist

• Sign-off message is added to all commits.
• The commit history is clean with no merge commits.
  • How to rebase your commits
  • How to squash commits with rebase
• Uploaded screenshots from before and after for UI changes.
• Test(s) added to branch, with before/after results included in PR description, for performance improvements where applicable.
• Documentation has been updated or is not required.
• Backports requested where applicable (critical bugfixes).
• Labels added where applicable (bug/enhancement).
• Milestone added for target version.

AI (if applicable)

• The content of this PR was partly or fully generated using AI
  • I have read the guidelines for AI-assisted contributions.
  • I have read Nextcloud's AI Contribution Policy.

[mgallien]

currently able to complete the initial synchronization
missing is proper communication between the openvfs fuse daemon and the desktop files client
will need investigation

[mgallien]

Current UI on linux to decide what type of synchronization the user wants to enable

@kra-mo We would want to offer an easy way to test the linux virtual files plug-in while recommending people to not use for production use (until it is ready for that)
any idea how to tune the UI to achieve that ?
I understand that this may not be easy to do 😄
I would still like to have an easy way of discovering the new feature (currently I modified the code as if the plug-in should be the default as seen in the screenshot)
previous experimental plug-in needed to modify the configuration file manually

[kra-mo]

@mgallien I think being straightforward with the text is probably the best idea. For example:

Virtual files (beta)
Download files on-demand. This feature is in an early preview. Recommended only with proper backups.

And don't have it be the default selection.

[mgallien]

I need to implement the suggestion for the selection of the synchronization types
I have now working hydration
so this is ready for testing
the disclaimer is that there is no guarantee, so feedback is very much welcome but be careful with your data

[mgallien]

there is a build and runtime dependency on https://github.com/opencloud-eu/openvfs