mgr/dashboard: rename 'Zone Group' labels to 'Zonegroup'

mgr/dashboard: rename 'Zone Group' labels to 'Zonegroup'

Fixes: https://tracker.ceph.com/issues/74249
Signed-off-by: Sagar Gopale <sagar.gopale@ibm.com>
(cherry picked from commit 60fa799d547eb4d94704767fdd659c3431dc0b6b)

 Conflicts:
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/create-rgw-service-entities/create-rgw-service-entities.component.html
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-multisite-zone-form/rgw-multisite-zone-form.component.html
	src/pybind/mgr/dashboard/frontend/src/app/ceph/rgw/rgw-multisite-zonegroup-form/rgw-multisite-zonegroup-form.component.html