Implement loading feature to all panels
- we have loading for text and annotation panel
- we need loading for all panels (metadata, image and tree/content)
- only the whole panel needs loading independent from content and possible tabs
how it should be:
- first empty state, then loading, then text (independent in each panel)
As (role of the user) I need (what has to be done) in order to (what I want to achieve with this feature).
Is this feature an enhancement of existing code or a completely new feature?
Add all related issues.