As an ELNer
I want to browse past (error) notifications whether I already have acknowledged them or not
so that I can read them any time.

Context:
Currently some error notification are transient and not persisted in the DB.
Also the ones saved in the DB but acknowledged are not visible to the user anymore.

Proposed enhancements:

• persist error notifications
• enhance notification browsing with pagination / filters / delete features
• limit pop-up notification to 3~4 newest (+ ellipsis) on page load