Fixes an error where the auth guard had race conditions
with the OpenSlides bootup routine (kinda hacky tbh)
Fixes false redirects in the Auth.Service
Also adjustes the file uploader to be a little more
usable.
Refactors the media file upload component into
a shared component to be used in both normal pages
and dialogs.
A dialog was addes into the media file "edit" view
to upload and set attachments on the fly.