Creating shares for attached files will litter the top-level view of all new users

[pReya]

Describe the bug When a user attaches a file in a card, the file will be uploaded into a local decks folder in the user's storage, and the file will then be shared with all other users. This will result in a very "dirty" and confusing top level folder for most new users within your Nextcloud instance. It makes for a bad onboarding experience, if there's dozens of files, whose origin is unknown to the user.

Expected behavior There should be a different way to add files to a Card (not selecting existing files), without creating a standalone share for every file.