Centralized media library

Is your feature request related to a problem? Please describe.
Currently managing attachments and any kind of media is very cumbersome in Decidim. Most administrators or system maintainers are not even aware of all the files uploaded to the system. You have to go into multiple different sections of the administrator panel in order to find even a subset of the material provided on the platform.

Another problem is that many times we have the need that an administrator would like to link an image, video or PDF document within a content page. Right now the content editor only allows adding images but when added, the administrators cannot find these images afterwards from the system without going through all the content areas there are in the administrator panel. Adding only images is also very limiting as many times administrators would also like to upload videos or PDFs.

Describe the solution you'd like
The ideal solution would be to provide a new section within the administrator panel called "Media library". This could be also integrated to the content editor so that the admins would have an easy way to upload content to the media library during the content creation itself.

All assets uploaded to the system should be visible within the media library. This includes attachments for processes and assemblies, attachments to the proposals or any other participant entered content, attachments to projects/results/etc. controlled by administrator users and any content embedded or added to the WYSIWYG editors throughout the admin panel.

The media library should work like a file manager in most operating systems, there should be possibility to add folders, subfolders and assets within these folders. The content added by participants could be uploaded to a predefined folder to keep these separated from the rest of the assets managed by administrators.

Describe alternatives you've considered
Right now we generally create a hidden assembly or process where admins can create attachments. They can upload the attachments there, take a link to those attachments, go to the section they want to edit and link the attachment there. This process is highly complicated and overly cumbersome for a regular administrator user. If the admin wants to attach a PDF to their text, the functionality should be where they edit that text.

Additional context
There are an endless amount of CMS systems where we can take inspiration on how to build this functionality and how to solve the problem properly. This is a real life need that we often struggle with.

Does this issue could impact on users private data?
No, but possibly in a positive way since admins could more easily monitor the content uploaded to the system and remove any content that is violating the platform rules or that includes private user data.

Funded by
N/A