mgr/dashboard: loading state for inventory card

mgr/dashboard: loading state for inventory card

show loading state when inventory details are being loaded. also don't
block the UI when inventories are not loaded.

Fixes: https://tracker.ceph.com/issues/72494
Signed-off-by: Nizamudeen A <nia@redhat.com>
(cherry picked from commit 05f7cb615b69e4f86a475b08f8f5baee2a1e2a32)

 Conflicts:
	src/pybind/mgr/dashboard/frontend/src/app/ceph/dashboard-v3/dashboard/dashboard-v3.component.html
 - resolve conflicts from popover changes
	src/pybind/mgr/dashboard/frontend/src/app/shared/components/card-row/card-row.component.html
 - resolve conflicts from the icon changes
	src/pybind/mgr/dashboard/frontend/src/app/shared/components/components.module.ts
 - only import inline loading component