Images upload & gallery link

The mediawiki version (1.34) powering this platform has been enhanced in order to support the storage of images and media files at a specific path, so that each organization can save all their images within a specific "folder" (under the main page itself of the organization, or whatever subpage within it) and can easily retrieve them from the visual editor media gallery, without mixing up their files with those of other organizations, and without file names conflicts.