Add the option to share custom properties across all users

[michelwilson]

This adds the ability to set custom properties to be shared across all users, as discussed in issue #4 . Let me know what you think!

[michelwilson]

Ah yes I replaced the checkbox with a combobox and never ran the tests again. I'll update the tests to fix this ...
Also I realized that this needs a migration to change the existing data to also use the fileId instead of path ... not sure how I'll approach that, but there's probably some way to get the fileId based on a path ... I hope :)

[jejusek]

Is a version for Nextcloud Hub II (23.0.0)?

[imaginabit]

I install this and works, but looks like search don't work as intended, In the main version it shows suggestion and can make searches like "property:value"

[amenk]

Is there a chance to get this merged?

[urrman]

Would you please merge the feature and continue to develop the whole app (support for NC 27 etc.) ?
Very useful app, please keep developing it.