Ability to import one or multiple configuration files via the configuration server's web interface

[mariusoe]

Currently, when a user wants to import one or multiple configuration files via the configuration server's web interface the following process has to be done:

• create a new file
• copy / paste the content into that file
• save the file

This process makes it quite tedious to import multiple files.

In this ticket, a feature should be implemented where the user can import one or multiple files at once without the need of creating and saving all files manually.

This could be implemented, for example, by allowing a user to import one or more files or folders via drag and drop or via a button in the configuration UI, which are then automatically created. In case whole folders are imported, their folder structure should be kept.