remove dependency of UI-Framework from module descriptor of ui-mediaeditor

User Story: as a SaaS user, I want to be sure that I'm using the latest stable version of the app so that I don't want to use the app based on the old legacy framework. 

Description: 
Our goal for 6.3 is to altogether remove the old UI framework; i.e. we will migrate all bundled apps to the M6 UI and remove the compatibility layer. This is equally important for SaaS where we do not want to run the legacy UI at all.

We need to remove dependency to ui-admincentral:

https://git.magnolia-cms.com/projects/PLATFORM/repos/ui/pull-requests/2133/overview

Removing this dependency will let us continue with the complete removal of the compatibility layer