Mediafiles refactoring

[bastianjoel]

Currently client/src/app/site/pages/meetings/pages/mediafiles/modules/mediafile-list/components/mediafile-list/mediafile-list.component.ts and client/src/app/site/pages/organization/pages/mediafiles/modules/organization-mediafile-list/components/organization-mediafile-list/organization-mediafile-list.component.ts are basically the same.

We should refactor this to prevent duplicate code.