Gallery view with thumbnails

[PVince81]

Improve the media viewer by providing a gallery view like the old gallery app had.

This requires a new extension point to allow an app to provide its own file list view: #2585

[PVince81]

Could use something like https://github.com/parys-github/vue-masonry-gallery for display, but this is more designed for pictures, not really file thumbnails.

[kulmann]

uikit also has masonry support in their grid component: https://getuikit.com/docs/grid#masonry

[pascalwengerter]

@tbsbdr needs product decision and prioritization if applicable

[kulmann]

Currently prioritized for after the first spaces features. Could be possible to have it for the oCIS GA, but might also be a little bit later. Might get prioritized higher, because it's a quite important feature...

[kulmann]

More recent ticket with much more details and mockups is #6126 - closing here.