Add loader when opening composition from URL #5910
Description
Feature Request
Is your feature request related to a problem? Please describe.
When opening the map with composition via hs-composition URL param, it sometimes takes "forever" until the composition file is loaded.
In such case, map remains blank and Layermanager seems empty. If the request fails in the end (times out), the error message is displayed. But until then, no clue is given to the user, if something is actually happening or not.
Describe the solution you'd like
Add loader into the Layermanager panel, optionally with some brief text like "Loading composition XY"
Describe alternatives you've considered
Show the loading in the "info" component (composition status in bottom left corner), which seems not to display anything useful now.
Additional context
https://www.poliruralplus.eu/map/playground?composition=http://www.poliruralplus.eu/rest/workspaces/jan5/maps/druhy_kultur