feat: improve loading of dialogs and tables
Created by: HejdaJakub
- Two new loader components were created and used across all apps (LoadingTableComponent and LoadingDialogComponent).
- The use case when some dialog includes also table was checked and it should work correctly (only one spinner should be visible).
- Another possible candidates for new loader components are "entity-detail-page" and "overview" components, but it is usually not possible to display some data (data are not fetched yet) during the loading behind the spinner for these components. Since it is not about UX but only about "consistency" or possible future easier changes, I did not implemented it in this PR.